It is possible to hide a role from displaying in Roles & Permissions by following the below steps:
Click the Admin Menu or Configuration, depending on how your system is configured then click on Roles & Permissions.
Click into a role you don't want to see other roles then search for the role you would like to hide.
Unselect the view icon then run batch updates.
📌Note: Once you have run the batch update, that role is not visible to the role this has been removed from.