Public Folder/Shared Calendars (Windows)
Switch to Folder View to see Public Folders.
Click on the ellipses in the bottom folder pane and select Folders to display the Public Folders.
To add Calendar to the Calendar view, right click each of the calendar in the public folders and Add to Favorites:
This will make the calendars viewable under Other Calendars in Outlook Calendar View:
Selecting the calendars under Other Calendars will overlay the calendars to get a single pane view: