Yes, using either the command line via the /Library switch, or the 20025 MCC command. The commands for your switching to the main library and your second library are, respectively:
mc17.exe /Library "Main Library"
mc17.exe /Library "TEST LIBRARY"
or via MCC command:
mc17.exe /mcc 20025,0
mc17.exe /mcc 20025,1
Add a new menu entry to Theater View, which calls the external program, as shown in the attached screenshots. Do this appropriately for each library.