For instance, on the History subtab, click "View Group Update", then hover the icon that opens the modal dialog. It says "Edit Member Values". But this is just a history, you can't edit.
As of r3453, I don't think is any longer an issue. For me, the tooltip for the icon says "View Member Values".
Fixed, rev3509
This bug was previously known as http://jira.rhq-project.org/browse/RHQ-1768