Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the shredded chicken, Buffalo wing sauce, and ranch dressing. Mix well until the chicken is evenly coated.
In a small saucepan, heat the mixture over low to medium heat until warmed through, about 5 minutes. Stir occasionally to prevent sticking.
Grease a baking dish with olive oil.
Slice the slider buns in half and place the bottom halves in the greased baking dish.
Spoon the Buffalo chicken mixture over the bottom halves of the buns evenly.
Sprinkle the shredded cheddar cheese on top of the chicken mixture, followed by the sliced green onions.
Place the top halves of the slider buns over the cheese.
Bake in the preheated oven for 15-20 minutes, or until the cheese is melted and the buns are lightly toasted.
Remove from the oven and let cool for a few minutes before slicing into individual sliders.
Serve warm with lettuce leaves if desired.