Since there is no hide when option in Navigator . To avoid show those view for
all users and give them a warning message, You use formula to determine which
Navigator should be opened according current user's user roles.
In the database launch properties, you may chose folder as the default
Put code like below in Database PostOpen event.
In this case you must have one user roles - "[manager]", you can also extend
this to more then two roles and navigators.