Cut the roast into quarters; place in a greased 5-qt. slow cooker. In a bowl, combine barbecue sauce, preserves, green pepper, onion, mustard and brown sugar; pour over roast. Cover and cook on low until meat is tender, 6-8 hours. , Remove roast. When cool enough to handle, shred meat with two forks; return to slow cooker and stir gently. Cook, covered, 20-30 minutes longer. Skim fat from sauce. Serve beef and sauce on rolls.