Well, i decided to solve it that way:
Create two conditional fields, with each two conditions (self), so they will only show on a specific Tab, if it meets one of two criterias.
This seems to work.
The tab, on the other hand also should show only on two specific usergroups out of five.
So if you belong to Usergroup A (condition 1) you will see that tab and if you belong to Usergroup B (condition 2) you will see that tab as well.
Currently it only shows the Tab on condition 2, ignoring condition 1. The settings are the same, besides the Usergroup, of course. If i set condition 1 to CB Configuration and add the Usergroup A as condition 3, it will only show on Usergroup A and not in Usergroup B.
This is very confusing. Any idea? I could create a second Tab, but would have to create the fields a second time and linkt it to the second Tab, since a CB Field can only be attached to one Tab, not to two.
Thanks for help.