Hi
russellit! I think Family system is close to what you need. It allows you to gather objects under a common super-objet. For example : You have Monster1, Monster2, and Monster3 -> You can make a "Monsters" Family with all them. Then, when you change the visibility of "Monsters" it will be applied to Monster1, Monster2, and Monster3.
I'm not sure it was exactly what you needed, but if you just started to discover C2, you might have missed this feature like I did. <img src="{SMILIES_PATH}/icon_e_wink.gif" alt=";)" title="Wink">
Check out the manual page for detailed information : https://www.scirra.com/manual/142/families