VERIFIED in 5.8.4.3. I was able to create two groups/users (userA & userB) with User/Group ownership restrictions. Approval requests created by admin or userA were not visible to userB.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2018:1972