The second item on the menu is Departments.  

Departments can be added/removed or edited on this page.

Departments can be Added/Removed or Edited.

Adding a Department:

Click on the "+"  icon and empty fields are displayed.   Fill in the Reference ID

(any arbitrary number) and the name for the Department then click on the Floppy Disk save icon.

Remove a Department:

Click the Garbage Can icon beside any Department to remove it from the list.