Layer 3 tortillas in baking dish, overlapping as necessary and placing slightly up sides of dish (cut third tortilla in half). Spread about half of the beans over tortillas. Top with about half of the chicken mixture and half of the taco sauce. Layer with 3 more tortillas and remaining beans and chicken mixture. Place remaining 2 tortillas over chicken mixture, overlapping slightly (do not place up sides of dish). Pour remaining taco sauce over top. Sprinkle with remaining 1 1/2 cups cheese.