App.Module

@NgModule({
    imports: [
        BrowserModule,
        FormsModule,
        HttpModule,
        MainModule,
        routing
    ],
    declarations: [
        AppComponent,
        LoginViewComponent
    ],
    bootstrap: [AppComponent]
})

Main.Module

@NgModule({
    imports: [
        CommonModule,
        FormsModule,
        mainChildRouting
    ],
    declarations: [
        ListViewComponent,
        MainComponent,
        PatientDetailsComponent,
        UnitInfoComponent,
    ],
    providers: [
        DateService
    ]
})

App.Routes

const routes: Routes = [
    {
        path: 'login',
        component: LoginViewComponent
    },
    {
        path: 'main',
        component: MainComponent
    },
    {
        path: '',
        redirectTo: 'main',
        pathMatch: 'full'
    }
];

const mainChildRoutes: Routes = [
    {
        path: 'main',
        component: MainComponent,
        children:
        [
            {
                path: '',
                component: ListViewComponent,
            },
            {
                path: 'unit_list',
                component: UnitInfoComponent
            },
            {
                path: 'unit_info',
                children:
                [
                    {
                        path: '',
                        component: PatientListComponent
                    },
                    {
                        path: 'patient',
                        component: PatientDetailsComponent
                    }
                ]
            },
        ]
    }
];

export const routing: ModuleWithProviders = RouterModule.forRoot(routes, { useHash: true });

export const mainChildRouting: ModuleWithProviders = RouterModule.forChild(mainChildRoutes);