How can multiple system role management permissions be configured?

Is there some way to allow the management of multiple system roles at a time, like namespace_admins (ADS, UNSGroup) for a specific system role type or something like that?

The scenario is, that we have a custom target system with groups. But these groups are never ordered alone. That´s why each group has an identical system role. But until now I didn´t found a (simple) way to give permission to the target system owners.

Now we want these system groups be managed by these custom target system owners. 

The usage of product owners is not feasable, because the product owners will be diffrent from the target system owners.