New Twiddle

components.radio-button-item.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'li',
  
  actions: {
    select() {
	    this.get('parent').set('value', this.get('value'));
    }
  },
  
  isSelected: Ember.computed('parent.value', 'value', function() {
    return this.get('parent.value') === this.get('value');
  })
});

components.radio-button.js

import Ember from 'ember';

export default Ember.Component.extend({
  value: undefined,
  options: undefined
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  list: ['Option 1', 'Option 2', 'Option 3', 'Option 4']
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{radio-button options=list}}
<br>
<br>

templates.components.radio-button-item.hbs

<button {{action 'select'}}>{{value}}</button>
{{#if isSelected}}
  Selected!
{{/if}}

templates.components.radio-button.hbs

<b>Selected Option is {{value}}</b>

<ul>
{{#each options as |option|}}
	{{radio-button-item value=option parent=this}}
{{/each}}
</ul>

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember-template-compiler.js"
  }
}