This article will show you how to enable the Departments Tabs setting in order to show a Department tab at the top of the Appointment screen.
You will first need to set up your Department(s) before departments will be displayed on your Appointment calendar. If you haven't done this already, click here for a guide on how to set up Departments.
Go to Manager > Settings, and click into the Appointment Setup section
Click Show advanced options, then change the Department Tabs setting to Yes and click Save.