Place the pork shoulder in the slow cooker.
Add the chopped onion and minced garlic on top of the pork.
In a bowl, mix together the barbecue sauce, chicken broth, apple cider vinegar, Worcestershire sauce, brown sugar, chili powder, paprika, salt, and black pepper.
Pour the mixture over the pork in the slow cooker.
Cover and cook on low for 8 hours, or until the pork is tender and easily shreds with a fork.
Remove the pork from the slow cooker and shred it using two forks.
Return the shredded pork to the slow cooker and mix it with the sauce.
Serve the pulled pork on buns, tacos, or your favorite dish.