Turn Instant Pot on to the saute function. Saute onions and bell pepper, about 5 minutes. Add in spices and saute for 1 minute-- to bring out their flavors. Turn off saute function.
Place whole chicken breasts on top, and add in both cans of green chilies, diced tomatoes, tomato sauce, black beans, corn, chicken stock, and salt.
Turn on Instant Pot to High pressure for 8 minutes. When the time is up, allow to natural release.
Once the pressure has been released, remove chicken from pot and shred with a fork (it should shred very easily). Place chicken back into the pot, along with softened cream cheese and shredded cheese. Stir until everything is well combined.
Serve with crushed tortilla chips, cilantro, avocado, and a squeeze of fresh lime.