Yes, you should be able to put all relevant objects in a family, and use a for each object and layer condition to filter by layer to save whatever data you want to json or array or whatever your data storage of choice is.
I definitely recall an example project that had pretty much what you're looking for. Unfortunately I didn't make that particular file and this forum's search is pretty crap. Will see if I can find it.
Edit: Didn't find the thread, but did find the file - dropbox.com/s/vq06s6x9oc335id/saveSpritePositionToJSON.c3p
Sorry to the original creator, can't remember who it was.