actions

components.inner-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  scope: 'inner',
  actions: {
    fromOuter(){},
    clicked(){
    	console.log('clicked', this.get('scope'));
      this.get('fromOuter')();
    }
  }
});

components.outer-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  scope: 'outer',
  actions: {
  forInner(){
  	console.log('for inner', this.get('scope'));
  }
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outer-component}}
<br>
<br>

templates.components.inner-component.hbs

Inner
<button type="button" onClick={{action 'clicked'}}>Click Me</button>

templates.components.outer-component.hbs

Outer
// change to 'forInner' and it errors
{{inner-component fromOuter=(action 'forInner')}}

twiddle.json

{
  "version": "0.10.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.7.0",
    "ember-data": "2.7.0",
    "ember-template-compiler": "2.7.0"
  },
  "addons": {}
}