Place chicken thighs in 3 1/2 or 4-quart slow cooker. Sprinkle with taco seasoning mix. Top with beans, tomatoes, chiles and lime juice.
Cover; cook on Low setting for 7 to 8 hours.
Just before serving, place all topping ingredients in individual serving dishes. Remove chicken from slow cooker; place on large plate. Mash beans in slow cooker. Shred chicken with 2 forks; return to slow cooker and mix well.
To serve, have guests place chips on serving plates; spoon 1/2 cup chicken mixture onto chips. Top nachos with desired toppings. Chicken mixture can be held on Low setting for up to 2 hours.