A bug was discovered where tags in tag groups are not visible to assigned user groups. nolo reported the issue, providing screenshots to demonstrate the problem. JammyDodger provided repro steps to verify the issue, which included enabling tags_listed_by_group, creating a tag group with restricted visibility, and testing with a trust level 0 user. The expected behavior was for the trust level 0 user to see the tag group, but they were unable to do so. The bug was later fixed via a commit as reported by techAPJ.
But for trust_level_0 the the tag and tag group don’t show on the tags page. We also use tag groups to bundle tags on a component and they don’t show there either.