Open the Calendar.
Click on Calendar Options (in the upper right corner).
Select the Subscription tab.
In the section labeled Mailbox Subscription, you may only see one field that says Mailbox Name, but you can have many different mailbox/folder subscriptions. If someone has given you access to their calendar, you can add a subscription to a mailbox using the tilda sign (~), the user name, the slash sign (/) and then the Mailbox or Folder name.
In other words, the format is: ~username/FolderName
For example, if John Doe's email address is jdoe@csulb.edu, type ~jdoe/Calendar in the Mailbox Name field to view his calendar.
