The Monitor can be connected to just one server at a time. To monitor a different BSCW server, you have to switch over manually. Focusing the Monitor applet on a new BSCW server is done by that server. You have to initiate this "re-focusing" in the same way as starting the applet:
on the top button bar of your 
Folder on the new BSCW server to re-focus the Monitor applet.
Connecting the applet to the new BSCW server may take a moment or two. In the process you will be asked to provide your user name and password for that server.