There is no inheritance in place that duplicates the memberships when carrying out group nesting. This works the same as in AD. Just because having group nesting it does not mean that the group memberships will be duplicated.
If there really is a need to duplicate the memberships implicitly, the proposed method is to implement that via a custom process chain/script combination.
Speaking generally, group nesting reduces the number of group memberships in each of the groups but are flexible enough to use a single parent group in ACLs like on file level permissions. At least this is the common scenario in Active Directory and the Windows file permissions.