HEAT barbecue to medium heat.
POUR 2 Tbsp. dressing over chicken in shallow dish; turn chicken over to coat both sides of each breast. Refrigerate 15 min.
MIX remaining 2 Tbsp. dressing, barbecue sauce and marmalade.
GRILL chicken 12 to 15 min. or until done (170°F), turning occasionally and brushing with sauce mixture the last few minutes.