diff --git a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/base-table/base-table.component.ts b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/base-table/base-table.component.ts
index aa3ef7b..3562a11 100644
--- a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/base-table/base-table.component.ts
+++ b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/base-table/base-table.component.ts
@@ -127,7 +127,7 @@ export class BaseTableComponent<TModel, TApiService extends ApiService<TModel>>
     return this.mainGrid.api;
   }
 
-  set source(data: TModel[]) {
+  set source(data: any[]) {
     this.api.setSource(data)
   }
 
diff --git a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/group-table/group-table.component.ts b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/group-table/group-table.component.ts
index 3a84629..99992ba 100644
--- a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/group-table/group-table.component.ts
+++ b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/tables/group-table/group-table.component.ts
@@ -7,6 +7,7 @@ import { ColorModeService } from '../../../services/color-mode.service';
 import { CommonModule } from '@angular/common';
 import { FormsModule } from '@angular/forms';
 import { env } from '../../../../environments/environment';
+import { GroupOfUserService } from '../../../services/group-of-user.service';
 
 @Component({
   standalone: true,
@@ -16,8 +17,14 @@ import { env } from '../../../../environments/environment';
   styleUrl: './group-table.component.css'
 })
 export class GroupTableComponent extends BaseTableComponent<Group, GroupService> {
-  constructor(
-    service: GroupService, cModeService: ColorModeService) {
+  constructor(service: GroupService, cModeService: ColorModeService, private gouService: GroupOfUserService) {
     super(service, env.columnNames.group.complete, cModeService)
   }
+
+  fetchDataByUsername(username: string) {
+    console.log(username)
+    this.gouService.getByUsername(username)
+      .then(gos_list => gos_list.map(gos => gos.group))
+      .then(groups => this.source = groups)
+  }
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.html b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.html
index 96f9d0b..e481724 100644
--- a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.html
+++ b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.html
@@ -1 +1,26 @@
-<app-user-table #userTable [cellEditing]="cellEditing"></app-user-table>
\ No newline at end of file
+<div class="container-fluid text-center">
+    <div class="row m-0 p-0">
+        <div class="col-6">
+            <mat-tab-group>
+                <mat-tab label="Benutzer">
+                    <app-user-table #userTable [onSelectedRows]="usersOnSelectedRows"
+                        [cellEditing]="cellEditing"></app-user-table>
+                </mat-tab>
+            </mat-tab-group>
+        </div>
+        <div class="col-3">
+            <mat-tab-group>
+                <mat-tab label="Gruppen">
+                    <app-group-table #groupTable [initData]="initWithoutData"></app-group-table>
+                </mat-tab>
+            </mat-tab-group>
+        </div>
+        <div class="col-3">
+            <mat-tab-group>
+                <mat-tab label="Module">
+                    <app-module-table #moduleTable [initData]="initWithoutData"></app-module-table>
+                </mat-tab>
+            </mat-tab-group>
+        </div>
+    </div>
+</div>
\ No newline at end of file
diff --git a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.ts b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.ts
index f316c62..5e2e2e6 100644
--- a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.ts
+++ b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/components/user/user.component.ts
@@ -1,16 +1,21 @@
 import { AfterViewInit, Component, ViewChild } from '@angular/core';
-import { GuiCellEdit } from '@generic-ui/ngx-grid';
+import { GuiCellEdit, GuiSelectedRow } from '@generic-ui/ngx-grid';
 import { UserTableComponent } from '../tables/user-table/user-table.component';
 import { RefreshService } from '../../services/refresh.service';
+import { MatTabsModule } from '@angular/material/tabs';
+import { GroupTableComponent } from '../../components/tables/group-table/group-table.component';
+import { ModuleTableComponent } from '../../components/tables/module-table/module-table.component';
 
 @Component({
   standalone: true,
-  imports: [UserTableComponent],
+  imports: [UserTableComponent, MatTabsModule, GroupTableComponent, ModuleTableComponent],
   selector: 'app-user',
   templateUrl: './user.component.html',
   styleUrl: './user.component.css'
 })
 export class UserComponent implements AfterViewInit {
+  initWithoutData = () => { }
+
   cellEditing: GuiCellEdit = {
     enabled: true,
     rowEdit: (value: any, item: any, index: number) => {
@@ -21,6 +26,8 @@ export class UserComponent implements AfterViewInit {
     }
   }
 
+  private sUsername = null;
+
   constructor(private refreshService: RefreshService) { }
 
   ngAfterViewInit(): void {
@@ -31,4 +38,15 @@ export class UserComponent implements AfterViewInit {
   }
 
   @ViewChild("userTable") userTable!: UserTableComponent
+  @ViewChild("groupTable") groupTable!: GroupTableComponent;
+  @ViewChild("moduleTable") moduleTable!: ModuleTableComponent;
+
+  usersOnSelectedRows = (rows: GuiSelectedRow[]) => {
+    if (rows.length > 0) {
+      this.sUsername = rows[0].source.username;
+
+      if (this.sUsername != null)
+        this.groupTable.fetchDataByUsername(this.sUsername);
+    }
+  }
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/services/group-of-user.service.ts b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/services/group-of-user.service.ts
index 7669dbf..ade2161 100644
--- a/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/services/group-of-user.service.ts
+++ b/DigitalData.UserManager.API/ClientApp/user_manager_ui/src/app/services/group-of-user.service.ts
@@ -2,14 +2,14 @@ import { Injectable, Inject } from '@angular/core';
 import { HttpClient, HttpParams } from '@angular/common/http';
 import { GroupOfUser } from '../models/user-management.api.models';
 import { ApiService } from './user-management.api.service';
-import { Observable } from 'rxjs';
+import { Observable, firstValueFrom } from 'rxjs';
 import { UrlService } from './url.service';
 
 @Injectable({
   providedIn: 'root'
 })
 export class GroupOfUserService extends ApiService<GroupOfUser> {
-  constructor(http: HttpClient, urlService : UrlService) {
+  constructor(http: HttpClient, urlService: UrlService) {
     super(http, urlService.apiRoute.groupOfUser);
   }
 
@@ -29,4 +29,9 @@ export class GroupOfUserService extends ApiService<GroupOfUser> {
 
     return this.http.get<GroupOfUser[]>(this.baseUrl, { params, withCredentials: true });
   }
+
+  async getByUsername(username: string): Promise<GroupOfUser[]> {
+    const url = `${this.baseUrl}?username=${username}`;
+    return await firstValueFrom(this.http.get<GroupOfUser[]>(url, { withCredentials: true }));
+  }
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.API/Controllers/GroupOfUserController.cs b/DigitalData.UserManager.API/Controllers/GroupOfUserController.cs
index 7b9a447..5f7a0c5 100644
--- a/DigitalData.UserManager.API/Controllers/GroupOfUserController.cs
+++ b/DigitalData.UserManager.API/Controllers/GroupOfUserController.cs
@@ -37,10 +37,17 @@ namespace DigitalData.UserManager.API.Controllers
         public override Task<IActionResult> GetAll() => base.GetAll();
 
         [HttpGet]
-        public async Task<IActionResult> GetAll([FromQuery]bool withUser = false, [FromQuery]bool withGroup = false)
+        public async Task<IActionResult> GetAll([FromQuery]bool withUser = false, [FromQuery]bool withGroup = false, [FromQuery] string? username = null)
         {
             try
             {
+                if (username is not null)
+                    return await _service.ReadByUsernameAsync(username).ThenAsync(Ok, IActionResult (m, n) =>
+                    {
+                        _logger.LogNotice(n);
+                        return NotFound();
+                    });
+
                 return await _service.ReadAllAsyncWith(withUser, withGroup).ThenAsync(Ok, IActionResult (m, n) =>
                 {
                     _logger.LogNotice(n);
diff --git a/DigitalData.UserManager.Application/Contracts/IGroupOfUserService.cs b/DigitalData.UserManager.Application/Contracts/IGroupOfUserService.cs
index aa48951..856a295 100644
--- a/DigitalData.UserManager.Application/Contracts/IGroupOfUserService.cs
+++ b/DigitalData.UserManager.Application/Contracts/IGroupOfUserService.cs
@@ -12,5 +12,7 @@ namespace DigitalData.UserManager.Application.Contracts
         Task<DataResult<IEnumerable<GroupOfUserReadDto>>> ReadAllAsyncWith(bool user, bool group);
 
         Task<Result> HasGroup(string username, string groupname, bool caseSensitive = true);
+
+        Task<DataResult<IEnumerable<GroupOfUserReadDto>>> ReadByUsernameAsync(string username);
     }
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.Application/Services/GroupOfUserService.cs b/DigitalData.UserManager.Application/Services/GroupOfUserService.cs
index dd67d39..0602455 100644
--- a/DigitalData.UserManager.Application/Services/GroupOfUserService.cs
+++ b/DigitalData.UserManager.Application/Services/GroupOfUserService.cs
@@ -5,7 +5,6 @@ using DigitalData.UserManager.Application.Contracts;
 using DigitalData.UserManager.Application.DTOs.GroupOfUser;
 using DigitalData.UserManager.Domain.Entities;
 using DigitalData.UserManager.Infrastructure.Contracts;
-using Microsoft.Extensions.Localization;
 
 namespace DigitalData.UserManager.Application.Services
 {
@@ -63,5 +62,12 @@ namespace DigitalData.UserManager.Application.Services
 
             return gous.Any() ? Result.Success() : Result.Fail();
         }
+
+        public async Task<DataResult<IEnumerable<GroupOfUserReadDto>>> ReadByUsernameAsync(string username)
+        {
+            var groups = await _repository.ReadByUsernameAsync(username);
+            var groupDtos = _mapper.MapOrThrow<IEnumerable<GroupOfUserReadDto>>(groups);
+            return Result.Success(groupDtos);
+        }
     }
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.Infrastructure/Contracts/IGroupOfUserRepository.cs b/DigitalData.UserManager.Infrastructure/Contracts/IGroupOfUserRepository.cs
index 886d6ab..c47f06e 100644
--- a/DigitalData.UserManager.Infrastructure/Contracts/IGroupOfUserRepository.cs
+++ b/DigitalData.UserManager.Infrastructure/Contracts/IGroupOfUserRepository.cs
@@ -14,5 +14,7 @@ namespace DigitalData.UserManager.Infrastructure.Contracts
         Task<IEnumerable<GroupOfUser>> ReadAllAsyncWithUser();
 
         Task<IEnumerable<GroupOfUser>> ReadAllAsyncWithGroupAndUser();
+
+        Task<IEnumerable<GroupOfUser>> ReadByUsernameAsync(string username);
     }
 }
\ No newline at end of file
diff --git a/DigitalData.UserManager.Infrastructure/Repositories/GroupOfUserRepository.cs b/DigitalData.UserManager.Infrastructure/Repositories/GroupOfUserRepository.cs
index 8b92ead..87e9ebd 100644
--- a/DigitalData.UserManager.Infrastructure/Repositories/GroupOfUserRepository.cs
+++ b/DigitalData.UserManager.Infrastructure/Repositories/GroupOfUserRepository.cs
@@ -12,9 +12,15 @@ namespace DigitalData.UserManager.Infrastructure.Repositories
         {
         }
 
+        //TODO: making it public and having it in the interface is against Clean Architecture. Make it private
         public IQueryable<GroupOfUser> ReadByGroupId(int groupId)
         {
-            return _dbSet.Where<GroupOfUser>(mou => mou.GroupId == groupId);
+            return _dbSet.Where(mou => mou.GroupId == groupId);
+        }
+
+        private IQueryable<GroupOfUser> ReadByUsername(string userName)
+        {
+            return _dbSet.Where(gou => gou.User!.Username == userName).Include(gou => gou.Group);
         }
 
         public async Task<IEnumerable<GroupOfUser>> ReadByGroupUserIdAsync(int groupId, int userId)
@@ -26,6 +32,8 @@ namespace DigitalData.UserManager.Infrastructure.Repositories
 
         public async Task<IEnumerable<GroupOfUser>> ReadAllAsyncWithUser() => await _dbSet.Include(gou => gou.User).ToListAsync();
 
-        public async Task<IEnumerable<GroupOfUser>> ReadAllAsyncWithGroupAndUser() => await _dbSet.Include(gou => gou.Group).Include(gou => gou.User).ToListAsync();        
+        public async Task<IEnumerable<GroupOfUser>> ReadAllAsyncWithGroupAndUser() => await _dbSet.Include(gou => gou.Group).Include(gou => gou.User).ToListAsync();
+
+        public async Task<IEnumerable<GroupOfUser>> ReadByUsernameAsync(string username) => await ReadByUsername(username).ToListAsync();
     }
 }
\ No newline at end of file