Line loaf pan, 9x5x3 inches, with plastic wrap, leaving 1 inch of plastic wrap overhanging at 2 opposite sides of pan. Spread orange peel dough evenly in bottom of pan. Spoon chocolate-nut dough evenly over orange peel dough; carefully spread. Spoon chocolate chip dough evenly over chocolate-nut dough; carefully spread. Cover and refrigerate at least 2 hours until chilled.