Place the chicken breasts in the bottom of the slow cooker. Add the chicken broth, diced tomatoes with green chilies, black beans, corn, onion, garlic, chili powder, cumin, and salt.
Stir gently to combine everything around the chicken. Cover and cook on low for 6 to 7 hours until the chicken is very tender.
Remove the chicken from the slow cooker and shred it with two forks. Return the shredded chicken to the pot and stir in the lime juice.
Ladle the soup into bowls and top each serving with diced avocado, chopped cilantro, tortilla strips, and shredded cheddar cheese.