Preheat an outdoor grill for medium heat and lightly oil the grate.
Rub chicken with 2 tablespoons barbecue sauce on each side. Place each chicken breast on a large square of heavy-duty or nonstick aluminum foil. Top each with 1 pineapple ring and 1 bell pepper ring. Lightly drizzle additional barbecue sauce on top of each and season with black pepper.
Pull foil up around the sides of chicken and double fold the top. Fold the ends securely to contain juices, while leaving room inside the packet.
Cook packets on the preheated grill over medium to low heat for 15 minutes or until chicken is no longer pink inside and juices run clear. Cut an opening in the packets to allow steam to escape before opening. Serve warm.
