Preheat the oven to 350°F / 175°C. Lightly grease a 9-by-13-inch baking dish with nonstick cooking spray, butter, or oil.
Add the cooked shredded chicken and ¾ cup barbecue sauce to a bowl. Toss until the chicken is evenly coated. Set aside the remaining ¼ cup BBQ sauce for serving.
Without separating the rolls, slice the entire sheet of Hawaiian rolls horizontally using a serrated knife. Place the bottom half of the rolls in the prepared baking dish.
If using ranch dressing, spread it over the bottom rolls. Sprinkle half of the cheddar and mozzarella cheese evenly over the rolls.
Spread the BBQ shredded chicken evenly over the cheese. Top with crumbled bacon, sliced red onion if using, and the remaining cheese.
Place the top half of the slider rolls over the filling.
In a small bowl, stir together the melted butter, Worcestershire sauce, garlic powder, parsley, and honey if using. Brush the mixture evenly over the tops of the rolls.
Cover the baking dish loosely with aluminum foil. Bake for 15 minutes.
Remove the foil and bake for 8 to 10 more minutes, until the cheese is melted and the rolls are warm and lightly golden.
Let the sliders rest for 3 to 5 minutes. Slice into 12 individual sliders and serve warm with the remaining BBQ sauce, ranch dressing, pickles, or coleslaw.