The user Role Manager feature allows you (the business owner) to create roles with desired permissions in BookOn.
You can assign your staff to these roles afterwards. You can decide which items on the dashboard should be available for the Staff, or staff can see whom appointments, customers, etc. Staff either can see their own appointments, customers, etc,. or can see the all. It is also possible to restrict staff to see none of the appointments, customers, etc.
Each module can be adjusted to be visible or invisible for staff on the staff dashboard.