New Twiddle

components.inner-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  didRender() {
    console.log('inner', this.elementId, 'didRender', this.$().html());
  }
});

components.outer-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  didRender() {
    console.log('outer', this.elementId, 'didRender', this.$().html());
  }
});

controllers.application.js

import Ember from 'ember';

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

templates.application.hbs

{{outer-component}}

{{#outer-component}}
  HA{{inner-component}}AH
{{/outer-component}}

templates.components.inner-component.hbs

I AM INSIDE

templates.components.outer-component.hbs

I AM OUTSIDE
{{#if hasBlock}}
	{{yield}}
{{else}}
  {{inner-component}}
{{/if}}

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"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}