New Twiddle

components.comic-publishers.js

import Ember from 'ember';

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

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  publishers: [
    Em.Object.create({
      name: "DC Comics",
      superheros: [
        Em.Object.create({name: "Superman"}),
        Em.Object.create({name: "Batman"}),
        Em.Object.create({name: "Flash"})
      ]
    }),
    Em.Object.create({
      name: "Marvel Comics",
      superheros: [
        Em.Object.create({name: "Iron Man"}),
        Em.Object.create({name: "Black Widow"}),
        Em.Object.create({name: "Thor"})
      ]
    }),
	],
  actions: {
    selectSuperhero(superhero, publisher) {
      alert('selected ' + superhero.get('name') + ' hero of ' + publisher.get('name'));
    }
	}
});

templates.application.hbs

<h1>Superheroes</h1>
{{comic-publishers publishers=publishers selectSuperhero=(action 'selectSuperhero')}}

templates.components.comic-publishers.hbs

{{#each publishers as |publisher|}}
  <h2>{{publisher.name}}</h2>
  {{superhero-list superheroes=publisher.superheroes select=(action 'selectSuperhero' publisher}}
{{/each}}

twiddle.json

{
  "version": "0.9.3",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.6.0",
    "ember-data": "2.6.1",
    "ember-template-compiler": "2.6.0"
  }
}