Mix the chicken broth, buffalo sauce, ranch seasoning, and beans together in a pressure cooker or crockpot before adding the chicken breast. Pressure cook on HI for 10-12* minutes with quick release pressure or slow cook on HI for 2.5-3 hours until the chicken reaches 165ºF.
Transfer the cooked chicken to a bowl to shred. Turn on the sauté function to reduce the remaining beans and liquid while you shred the chicken. (If you're using a crockpot, you can transfer to a sauce pan over medium-high heat on the stovetop.)
Once the chicken is shredded and the remaining beans/liquid has thickened, add the chicken back to the beans and stir everything together.
For the nachos, fill a baking sheet with the tortilla chips and top with 2 oz shredded cheese. Add 16 oz** of the buffalo chicken and beans, followed by another 2 oz shredded cheese. Bake for 6-8 minutes at 400ºF until the cheese is fully melted. Top with green onion and blue cheese crumbles, if desired.