In a slow cooker, place the chicken breasts at the bottom. Sprinkle the ranch seasoning mix over the chicken evenly.
Add the cream of chicken soup, diced tomatoes with green chilies, black beans, corn, chicken broth, garlic powder, onion powder, salt, and pepper. Stir to combine all the ingredients.
Cover the slow cooker and cook on low for 6-8 hours or on high for 3-4 hours, until the chicken is cooked through and tender.
Once cooked, remove the chicken breasts and shred them using two forks. Return the shredded chicken to the slow cooker.
Add the softened cream cheese and shredded cheddar cheese to the slow cooker. Stir until the cheeses are melted and well combined.
Taste and adjust seasoning if necessary. Serve hot, garnished with chopped green onions and cilantro if desired.