To view all Calendars for a user you have to do it by adding yourself as a delegate. Instructions are:
1.) Launch Entourage
2.) Go to Tools -> Accounts
3.) Choose Entourage account
4.) Select the "Delegate" tab
5.) Under "Users I am a delegate for" click the “add" button.
6.) Do a search for the user, select them, click advanced.
7.) For the server address https://email@example.com
8.) Click Ok, then choose Send & Receive