Place the chicken breasts in the CrockPot. Pour in the chicken broth, cover, and cook on low for 4-6 hours or until the chicken is fully cooked and tender.
Once cooked, remove the chicken breasts from the CrockPot, shred them using two forks, and set aside.
In a large mixing bowl, combine the cream of mushroom soup, cream of chicken soup, diced tomatoes with green chilies, chopped onion, chopped green bell pepper, garlic powder, onion powder, salt, and pepper. Mix until well combined.
Return the shredded chicken to the CrockPot and pour the sauce mixture over the chicken. Stir to combine.
Cook the spaghetti according to package instructions until al dente. Drain and add the cooked spaghetti to the CrockPot.
Stir in 1 1/2 cups of the shredded cheddar cheese. Mix until everything is evenly coated with the sauce.
Cover and cook on low for an additional 30-40 minutes until heated through and the cheese is melted.
Serve hot, topped with the remaining cheddar cheese and enjoy!