It is possible with the Supervisor module in the MEGA Administration tool to manage MetaModel filters (visiblity) and accesses (ability to create, update, delete) on a profile level.
On the environment level, you can indicate that users cannot see that MetaAttribute, but create a profile of users that see that MetaAttribute, then you link the concerned users to that profile.
OR
On the environment level, you make no specific indication (so by default all users can see that MetaAttribute), but create a profile of users that cannot see that MetaAttribute, then link the concerned users to that profile.
There is no need to activate confidentiality on the environment just for this specific need.
