Heat oven to 325 degrees.
Butter the bottom of an 8-inch square glass pan thickly with the 1 tbsp. butter.
Sprinkle coconut over it evenly and press it down firmly.
Bake 10 to 15 minutes or until golden.
Cool while preparing filling.
Prepare pie filling as directed on package except beat the egg yolks into the 2 1/2 cups milk and use this for the liquid.
Cook as directed on package then stir in grated grapefruit and orange rinds.
Cool.
Dry grapefruit and orange sections well on paper towelling.
Keep about 5 grapefruit and 5 orange sections aside to garnish the pudding.
Cut the remaining sections into about 3 pieces each and fold them into the pudding.
Spoon the pudding over the coconut.
Heat oven to 425 degrees.
Beat egg whites until fluffy.
Beat in sugar gradually, beating well after each addition.
Beat until stiff and glossy.
Spoon on top of pudding and spread it to cover, making swirls.
Bake 5 to 8 minutes or until meringue is nicely browned.
Cool.
Garnish with grapefruit and orange sections and spoon into serving dishes.