Test Changeset on nested properties

controllers.application.js

import Ember from 'ember';
import Changeset from 'ember-changeset';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  init(){
  	this._super();
  	
    let data = { superfields: { first_name: 'Jim', last_name: 'Bob' } };
    let changeset = new Changeset(data);
    this.data = data;
    this.changeset = changeset;
	}
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
      <h1>{{changeset.superfields.first_name}} {{changeset.superfields.last_name}}</h1>
      <h1>{{data.superfields.first_name}} {{changeset.superfields.last_name}}</h1>
      <input
        id="first-name"
        type="text"
        value={{changeset.superfields.first_name}}
        onchange={{action (changeset-set changeset "superfields.first_name") value="target.value"}}>
      {{input id="last-name" value=changeset.superfields.last_name}}
<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"
    "ember-changeset": "2.1.2",
    "ember-changeset-validations": "2.1.0"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}