New Twiddle

controllers.application.js

import Ember from 'ember';

const Foo = Ember.Object.extend({
  array: [1,2,3]
});
const Bar = Foo.extend({
  array: [2,3,4] 
});
const Baz = Foo.extend({
  //array: this._super.array.map(x => 1)
  array: Foo.array
});

export default Ember.Controller.extend({
  obj1: Foo.create(),
  obj2: Bar.create(),
  obj3: Baz.create()
});

templates.application.hbs

Obj1 {{obj1.array}}<br>
Obj2 {{obj2.array}}<br>
Obj3 {{obj3.array}}<br>
{{outlet}}
<br>
<br>

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"
  }
}