hi @Philippe CRAVEโ a user can see a notebook only if they have permission to that notebook. Else they won't be able to see it. Unfortunately there is no possibility for a normal user to see the notebooks attached to a cluster if they do not have permissions for the notebook. This is a good feature request. I can raise thin internally to develop it in the future.
For now, if you want a user to see the notebooks then they need to grant at least read permissions to the notebook.