Thanks for the tip. I think that did the trick. As a test I set up two cohort lists with two different sets of participants. I then set up a course (course A) and added these cohorts as users. I then can "duplicate" this combination of users by setting up a new cours (course B) as a meta course that grabs its participants from course A. This way we can basically set up combined participant groups that can be plugged into when teachers set up their courses.