That still has to be done with our regular visibility.
What you can do is the following:
1. Create two or more organization
2. One organization is for general visibility, add the Users group to that.
3. Apply visible to the Entity Groups as a whole except for Things, apply to all Things BUT the ones to be hidden
4. Apply visible to the Entities that need to be hidden it on an individual level with the other Organizations.
Thanks for the response. This is as I expected. However, it would be nice if this could be added as an enhancement in the future. It would be nice if the visibility functionality could be improved to allow "rejected" instead of just "allowed". Then we would not have to remove Users from Everyone. We could just add an entry for the Things we want to hide by using isPermitted="false" on the visibility setting. Or we would only have to edit one entity instead of all the rest. Has anyone else made queries regarding this?