As the documentation page you provided, you can render one controller within another using:
{{ render_esi(controller('YourBundle:Default:news', { 'max': 5 })) }}
You can also use a route name instead of the controller reference:
{{ render_esi(url('latest_news', { 'max': 5 })) }}
However, you will need to set up a gateway cache for ESI to work.