Place the chicken breasts in the bottom of the crock pot.
In a medium bowl, whisk together barbecue sauce, chicken broth, apple cider vinegar, brown sugar, smoked paprika, garlic powder, onion powder, salt, and black pepper until well combined.
Pour the sauce mixture evenly over the chicken breasts in the crock pot.
Cover and cook on low for 4 hours, or until the chicken is tender and easily shredded with a fork.
Remove the chicken breasts from the crock pot and shred them using two forks.
Return the shredded chicken to the crock pot and stir to coat it evenly with the sauce.
Keep the crock pot on warm until ready to serve.
To assemble sandwiches, place a generous amount of shredded chicken on the bottom half of each sandwich bun.
Top with a slice of cheddar cheese and a dill pickle slice if desired.
Place the top half of the bun on the sandwich and serve immediately.