Preheat oven to 350 degrees. Line with a large baking sheet with a silicone liner or parchment paper.
Roll out crescent dough on wax paper to form a rectangle. If not using crescent dough sheet, press the seams together.
In a large bowl mix together chicken, cheese, BBQ sauce and onion. Spread evenly on top of the crescent dough, leaving about 1/2 inch border.
Carefully roll up lengthwise. Gently press in end to the side of dough to prevent opening.
Mix butter with garlic powder and parsley. Brush some of the butter over top.
Using a sharp knife carefully cut into 9-12 equal size slices (1 inch – 1 1/2 inch thick). Place slices cut side down on baking sheet. Brush tops with any remaining butter.