To be clear, I have a selection and I want to move its content, the content from multiple layers. I know In my version of GIMP that I can't actually select multiple layers, but I can chain and group them. I tried ctrl-alt-clicking in both cases, but the selection content didn't move. I also tried floating the selection, but that didn't work presumably because GIMP only allows one floated layer at a time. The only thing I've succeeded in is moving the entire layers together, but I only want the selection area moved.
I've been scraping Google for a while now and haven't found anything. Plenty of tips on how to group and chain but nothing on moving content of selections within them.
I'm using GIMP 2.8.18 on Windows 7. I'm not opposed to upgrading GIMP version or installing a plugin if necessary. Any help would be greatly appreciated.