Hi, fdbob! Welcome to iPF!
Try to go to the album where you want to delete it. I did so with one of my Snapseed pictures. It was deleted in Snapseed, but stayed in my archive.
Are you trying to delete the picture in the camera roll, but keep it in a folder? The photos in your folders are really just links to the original in the camera roll, that's why deleting it in the camera roll will delete it in every folder as well.