Idea ID 2806005
You can assign several role to a single user or to an group.
However, this cannot be reported, nor it can be extracted by using CSV or XLS Exports, as you are not able to show this information.
I can think of two possible use cases which basically require the same idea:
1) Report or Search possibility to get an idea of which users are assigned to which roles
2) Audit report to provide an information who has tenant admin permissions