You can switch your current org unit by changing your active course calendar. Select a course from the calendar menu to activate it.

Active calendars in the calendar menu

Note Even when you set your current calendar, the calendar content area will, by default, show events from all the courses listed in the calendar menu. To filter the view, click the Remove Calendar icon by the course's name you wish to remove from view in the calendar menu.

Set your active course calendar

Click on a course name from the calendar menu.