New Twiddle

components.action-bar.js

import Ember from 'ember';

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

components.action-foo.js

import Ember from 'ember';

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

components.action-more.js

import Ember from 'ember';

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

components.actions-menu.js

import Ember from 'ember';

export default Ember.Component.extend({
  mainActions: ['foo'],
  moreActions: ['bar'],
});

components.entity-actions.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.get-actions.js

import Ember from 'ember';

export function getActions(params) {
  const actionNames = params[0];
  const actions = params[1];

  const out = actionNames.reduce((accum, actionName) => {
    accum[actionName] = actions[actionName];
    return accum;
  }, {});

  console.log('out', out);
  return out;
}

export default Ember.Helper.helper(getActions);

templates.application.hbs

{{#actions-menu as |mainActions moreActions|}}
  <h3>Main actions:</h3>
  {{mainActions.foo}}
  {{mainActions.bar}}
  
  <h3>More actions:</h3>
  {{moreActions.foo}}
  {{moreActions.bar}}
{{/actions-menu}} 

templates.components.action-bar.hbs

<button>Bar</button>

templates.components.action-foo.hbs

<button>Foo</button>

templates.components.action-more.hbs

{{yield}}

templates.components.actions-menu.hbs

{{#entity-actions as |actions|}}
  {{yield
    (get-actions mainActions actions)
    (get-actions moreActions actions)
  }}
{{/entity-actions}}

templates.components.entity-actions.hbs

{{yield (hash
  foo=(component "action-foo")
  bar=(component "action-bar")
)}}

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}