you could set a variable "type" to the familly, and set every object A to type=1, object B to type=2, and so on.
then you can do this:
"family type=2" ----> and only objects with type=2 would be called.
Just be sure to set the proper numbers to the objects. if they are already in the layout on start, you can set them manually, but on creating them you'll need to "set type to X".