ngx-admin/src/app/pages/pages-routing.module.ts

import { RouterModule, Routes } from '@angular/router';
import { NgModule } from '@angular/core';

import { PagesComponent } from './pages.component';
import { DashboardComponent } from './dashboard/dashboard.component';

const routes: Routes = [
  {
    path: '',
    component: PagesComponent,
    children: [
      {path: '', redirectTo: 'dashboard', pathMatch: 'full'},
      {path: 'dashboard', component: DashboardComponent}
    ]
  }
];

@NgModule({
  imports: [RouterModule.forChild(routes)],
  exports: [RouterModule]
})
export class PagesRoutingModule {
}