The SL1 and SL2 commands isolate items of the same service or turn off the visibility of all items with the same service as the object(s) selected.
SL1 command
The SL1 command 
isolates the selected items' services by turning all other services off.
Example:
SL2 command
The SL2 command 
turns off the visibility of all items with the same service as the object(s) selected.
Example:
Note: Use the SHOWALL command to reinstate visibility of all objects.