By default, managers are able to see schedules for all locations, but Premium subscribers have the option to restrict their managers' view of the schedule to just those assigned within a manager's profile.
To change this setting, go to Dashboard > Schedule > Schedule Settings.
Scroll to the Visibility of schedules for managers section and you will see the option. Switch the toggle to No and your managers will only be able to view schedules for locations assigned in their profiles.
Remember to save your changes!