“Nested Groups” in Active Directory are similar to “Composite Roles” in SAP (and similar concepts in other sources/systems). By “definition” these should NOT be expanded in IDN or any concern of IDN. These constructs are a feature in the target system and should be addressed directly in the target system considering the nested roles/groups can’t be changed directly in IDN.
As an alternative, IDN Access Profiles/Roles could be used to replace nesting in target applications, but this is a significant lift for the migration and eliminates the benefits (and challenges) of using the native functionality. There are definitely some pros/cons to using nested groups in AD, but these are left to AD vs. being exposed/handled in IDN.