Contextual Double Yield

components.thing-item\.js

import Component from '@glimmer/component';

export default class extends Component {
}

components.thing-list\.js

import Component from '@glimmer/component';

export default class extends Component {
}

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
<br>
<br>
<br>
{{#thing-list as |t|}}
	{{t.thing-item}}
  {{t.thing-item}}
  {{t.thing-item}}
{{/thing-list}}

templates.components.thing-item\.hbs

<p>context: {{@context}}</p>

templates.components.thing-list\.hbs

<section>
	<h2>List A</h2>
  {{yield (hash thing-item=(component "thing-item" context="a"))}}
</section>
<section>
	<h2>List B</h2>
  {{yield (hash thing-item=(component "thing-item" context="b"))}}
</section>

twiddle\.json

{
  "version": "0.17.0",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.17.0",
    "ember-template-compiler": "3.17.0",
    "ember-testing": "3.17.0"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}