Show part of page in content for access group


I got problem. I searched here and google and nothing helps. Seems I do step by step like I found but not works as I expect.

I got private area where I login and this works.
I got 2 access groups with:

    aaa: 'true'
    bbb: 'true'

My site I set to access to:

access: true
site.bbb: true

and on this site in content I like to show part of it, so I use twig:

<p>AAA and BBB see this</p>
{% if grav.user.authorize('') %}
<p>AAA only</p>
{% endif %}

In theory it should work but it does not and show up all for AAA and BBB.