Preheat oven 375 degrees and grease a 13 x 9 baking dish. Spread pineapple in heavy syrup in bottom of greased dish. Spoon the pie filling evenly over pineapple. Sprinkle dry cake mix evenly over pineapple and pie filling, then sprinkle nuts over fruit mixture. Slice butter or margarine into thin slices and put evenly over the top of mixture. Bake 50 minutes or until golden. Serve warm. Makes 12 servings.