There are browser extensions that simply lets you save all (or some selection of) images that load on a website. Maybe that's good enough if you can't find one

There are browser extensions that simply lets you save all (or some selection of) images that load on a website. Maybe that's good enough if you can't find one that has proper support for Facebook groups. I imagine you could quite quickly just click through the material and save it. Won't work for text or metadata like descriptions/titles I guess...