[Plugin: Members] read_private_XXX ??

I am using buddypress 1.6.1 and bbpress 2.1.2.

Now I would like to restrict the view of private forums: Only certain roles can see the thread’s content. Everybody can see the topics, but once clicked on a topic, you should get an error page unless you are assigned to that certain role.

Is this possible with the Members plugin?

I see Capabilities like: read_private_forums, read_private_replies, read_private_topics, read_private_pages and read_private_posts.

But no matter what I check or uncheck, users of that role can either see the whole forum or nothing.

Any ideas how to get this done?

Thanks for you help! ??

https://www.ads-software.com/extend/plugins/members/