Brush pineapple with butter and sprinkle with ½ teaspoon seasoning.
Grill over medium direct heat, 6 to 7 minutes, turning every 2 minutes to char all sides.
Remove and cool enough to handle.
Chop pineapple and combine with bell pepper, onion and cilantro; squeeze lime juice over all and toss to mix.
Refrigerate if not serving immediately.
Generously season chicken breasts with 1 tablespoon seasoning.
Grill over direct medium heat keeping lid closed as much as possible, 16 to 20 minutes, turning once, until chicken is cooked through and internal temperature is at least 170°F.
Remove chicken from grill and let rest for 5 minutes before serving.