Place the chicken breasts at the bottom of the slow cooker.

Add the black beans, kidney beans, corn, diced tomatoes, buffalo sauce, onion, garlic, cumin, chili powder, smoked paprika, salt, and pepper on top of the chicken.

Stir the ingredients gently to combine, ensuring the chicken is mostly covered.

Cover the slow cooker and cook on low for 6-8 hours or high for 3-4 hours, until the chicken is cooked through and tender.

Once cooked, remove the chicken and shred it using two forks. Return the shredded chicken to the slow cooker and stir to combine.

Taste and adjust seasoning if necessary.

Serve hot, topped with shredded cheddar cheese, a dollop of sour cream, and chopped green onions.