Place the chicken breasts, hot sauce, and butter into a 4-quart or larger slow cooker. Cover and cook on HIGH for 4 hours or LOW for 8 hours.
While the chicken is cooking, prepare the ranch dressing. Whisk together the ranch dressing mix, buttermilk, mayo, and pepper in a medium bowl until smooth. Cover and refrigerate for later.
When the chicken is done cooking, use 2 forks to shred it right in the slow cooker. Then mix it into the sauce. Set that aside for now.
Preheat your oven to broil.
Split the slider buns in half horizontally. Place all the bun halves cut side up on a baking sheet and then brush them with olive oil.
Place the baking sheet under the broiler for 5-7 minutes, watching carefully! The buns are ready when they're golden brown.
Remove the buns from the oven. Cut off the end of the garlic clove and then rub the garlic onto the browned area of the buns. (see note)
Add some buffalo chicken to the bottom buns. Then top with ranch dressing and place the top buns on the sliders.
Serve immediately with carrot sticks, celery sticks, and extra ranch.
When serving these sliders on a buffet, I put the slider bun tops and bottoms back together after rubbing on the garlic and then arrange the buns on a platter. Guests can build their own sliders since all the components are ready to go.