Is there a way to create an extra field in the "Edit User" page which allows the administrator to restrict any Calendar Contributor Role Users to specific Categories?
Think of this Scenario:
There are 10 clients each client has a user accounts with the role of Calendar Contributor. Each client can have access to 1 or more Categories.
In this example we will say 1 category per client (user).
Each client can manage and view their own category but not the others.
The purpose behind this is to keep each client's events separated from each other and private. The only user that can view and manage all events for all categories are administrator accounts.