Preheat the oven to 350°F (175°C).
In a large bowl, combine the shredded chicken, buffalo sauce, ranch dressing, salt, and pepper. Mix well until the chicken is evenly coated.
In a skillet, heat the olive oil over medium heat. Add the buffalo chicken mixture and cook for about 5 minutes, stirring occasionally, until heated through.
Slice the slider buns in half and place the bottom halves in a baking dish. Spoon the buffalo chicken mixture evenly over the buns.
Sprinkle the shredded cheddar cheese on top of the chicken, then add the sliced green onions.
Place the top halves of the buns over the cheese and chicken. Cover the baking dish with aluminum foil.
Bake in the preheated oven for 15 minutes. Remove the foil and bake for an additional 5-10 minutes, or until the cheese is melted and the tops are golden brown.
Remove from the oven, let cool for a few minutes, then slice and serve warm.