I have been looking for this movie for DECADES!
I remember this scene, with details that may or may not be accurste, but I will give the basics.
There is a group of people (sci-fi feel) and one of them is pulled out (taken) from under a door. The group (or member of the group) later travel and come across a fire and man with meat roasting and eating. They/He conclude the meat is their friend who was pulled under the door.