When running reports that show groups, and selecting to expand the groups in the report, there are no AD group members shown, or the group membership is incorrect.
If you have not run an Active Directory Discovery you need to select the option to collect group members during your Discovery (Computer, MS SQL, NTFS, Registry). If an AD Discovery has been run, confirm the 'Groups and members' option is selected on the Scopes page of the AD discovery.
Please note, collecting group membership information from all of the Discoveries, with the exception of the AD Discovery, will increase the amount of time it takes the Discovery to complete. If you are licensed for Active Directory, it would be best to run an Active Directory Discovery as the reports will reference the group membership data collected by the AD Discovery, regardless of which report type you run.
If you need to report on just the local groups and local group members, selecting the Accounts option in the Computer discovery will collect the local groups on the targeted computers.