You can view any users notebook as long as you are in the same group as them.
To do this:
Click My Actions
Click Notebook
If you are using windowed mode:
In the right hand Window, click Actions
Click View Other notebook
If you are using full screen mode:
In the right hand Window, click View Other notebook
Find and highlight the user's notebook you want to view and click Select
If there are no other users or the user you are looking for isn't listed, please speak to your companies system administrator to add you into the same group.