New Twiddle

components.foo-bar.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
    firstOne() {
      console.log('firstOne called');
      this.sendAction('secondOne', 'two');  
    },
    
    secondOne(arg) {
      console.log('secondOne called', arg); 
    }
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  actions: {
    secondOne(arg) {
      console.log('controller secondOne', arg); 
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{foo-bar secondOne="secondOne"}}
<br>
<br>

templates.components.foo-bar.hbs

<button {{action "firstOne"}}>Click</button>

twiddle.json

{
  "version": "0.8.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}