SAP standard table for user group and system in CUA

Hello experts,

I am trying to get a SAP standard table that have information for user group, system and userid.

I need to create a customized program which once executed, it will provide information of total number of created users for each user group in each system in the CUA landscape.. have tried table USZBVSYS but it does not have the user group information.

Appreciate related advice.

Thanks!