New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

router.js

import EmberRouter from '@ember/routing/router';
import config from './config/environment';

const Router = EmberRouter.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('route-a', function() {
    this.route('route-b', function() {
      this.route('route-d');
    });
    this.route('route-c');
  });
});

export default Router;

routes.route-a.js

import Ember from 'ember';

export default Ember.Route.extend({
});

routes.route-a.route-b.js

import Ember from 'ember';

export default Ember.Route.extend({
  renderTemplate() {
    this.render({ into: 'application' });
  }
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.outlet {
  border: solid 1px blue;
  padding: 10px;
}

#application-outlet {
  border-color: red;
}

templates.application.hbs

{{link-to "Route A" "route-a"}}
{{link-to "Route B" "route-a.route-b"}}
{{link-to "Route C" "route-a.route-c"}}
{{link-to "Route D" "route-a.route-b.route-d"}}
<br>
<br>
<div class="outlet" id="application-outlet">{{outlet}}</div>
<br>
<br>

templates.route-a.hbs

Route A

<div class="outlet">{{outlet}}</div>

templates.route-a.route-b.hbs

Route B (rendered in application outlet)

<div class="outlet">{{outlet}}</div>

templates.route-a.route-b.route-d.hbs

Route D (inside Route B)

templates.route-a.route-c.hbs

Route C (rendered in route-a outlet)

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}