In release at 3.7.12 or later, the users are unable to remove groups under the groups for which they have administer rights.
Release : 3.7.12 or later
Component : IM Data Aggregator
The fix for DE484964 is currently targeted for CA Performance Management 3.7.18.
This fix will allow groups to be created under the administered groups in the 3.7 release it is planned to be released in (this defect did not impact 20.2.x).
Note that this is subject to change and there are no release dates that can provided at this time