Stir together barbecued chicken, black beans, and 1/2 cup barbecue sauce in a medium bowl.
Place 1 tortilla in a lightly greased 10-inch springform pan, and spread with one-third chicken mixture.
Sprinkle with one-third each of tomatoes, green onions, and cheese. Repeat layers twice. Top with remaining tortilla, and gently press. Cover pan with aluminum foil.
Bake at 400 for 15 to 20 minutes or until golden brown.