The Staff role can be modified to allow access or take away access from certain actions. Below is a screenshot of what is available to you.
To edit your Staff Permissions:
Go to People > Staff from the navigation bar
Click on the Permissions button (Screenshot A)
If you unsure how the permission works, click the help icon (Screenshot B)
Check to box next to the permission you want to enable/disable
Viewing Appointments on Mobile
If you have enabled the permission for staff to view other appointments, make sure you go to the mobile app and check the names on the staff filter to see their schedules.