There is no option to see hidden attributes, such as consistency, professionalism, PA, CA within the game set-up.
You aren't supposed to have access to these through normal gameplay.
It is a setting that governs the visibility of player attributes that are visible on profiles. The "masking" in this sense is whether or not you can see all the attributes in the technical/physical/mental categories and their 1-20 scores or if these attributes are masked and through scouting or acquisition of knowledge about players this effect is lessened and eventually removed.