Hi Sabrina

Are you aware of dynamic audiences where rules can be used to define members of audiences. If the user no longer meets the rules then they are removed from the audience and if they are enrolled in a course by the audience they are unenrolled from the course. See https://help.totaralearning.com/display/TL9/Audiences#Audiences-Dynamicaudiences

If this isn't what you are meaning can you explain what you want to do in more detail.

regards