Description of suggested behaviour:
When you have multiple groups, create a modifier so that only one of the groups is allowed to be a parent for a user.

Example of suggested behaviour:
Say we have two groups group-a and group-b. When a user is a member of group-a and I add group-b to the user, I want LP to automatically remove group-a. Important here is that there is no specific order for the groups (which is the case in a track).

Just use /lp ... parent set

That will remove all groups right? I do not want to remove all groups, just the ones beloning to the same "set" of groups.

Then use /lp user <user> parent settrack <track> <group>

I guess that works, thanks!