so#45474821

components.my-component1.js

import Ember from 'ember';

export default Ember.Component.extend({ 
	prop1: 'abc'
})

components.my-other-component3.js

import Ember from 'ember';

export default Ember.Component.extend({
});

components.my-yield-component2.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';

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

helpers.my-helper.js

import Ember from 'ember';

export function myHelper(params/*, hash*/) {
  return `Hi there ${params[0]}`;
}

export default Ember.Helper.helper(myHelper);

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{my-component1}}
<br>
<br>

templates.components.my-component1.hbs

{{#my-yield-component2}}
    {{my-other-component3 field=(my-helper prop1)}}
{{/my-yield-component2}}

templates.components.my-other-component3.hbs

{{field}}

templates.components.my-yield-component2.hbs

<div>My component with yield</div>
<div>{{yield}}</div>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}