When I have a course with the following settings:

• Group mode: Separate groups
• Force group mode: Yes

And I prohibit the following capability for teachers:

• moodle/site:accessallgroups

When I create a BBB activity as a teacher, I should only be able to specify individual "User" participants with whom I share a group with (or can view on the course participants screen), but I can manually add users I don't share a group with/would otherwise be unable to access