This is man v. man because Georg Znaeym and Ulrich Von Gradwitz are from two feuding families that dislike each other for poaching on another's land. Their deciding who is going to shoot first.
This is man v. self because Georg Znaeym is contemplating with himself. Georg can't decide if he wants to find a kill Ulrich on his land.
This is man v. nature because Georg and Ulrich are trapped under a branch. Also it's man v. nature because a pack of wolves comes and eats the men.