In a medium sauce pan over medium heat, heat oil. Add garlic and cook until fragrant, 1 minute. Add barbecue sauce, pineapple juice, Worcestershire sauce and chili powder. Whisk to combine and cook until thickened slightly, 5 minutes. Add chicken to sauce pan and toss to coat.
Make cilantro-lime mayo: in a medium bowl, whisk together Duke’s Mayonnaise, lime juice, cilantro, and garlic. Season with salt.
Preheat oven to 350° and place bottom half of slider buns on a large baking sheet.
Build sliders: spread mayo mixture in an even layer on bottom buns. Top with an even layer of sauced chicken, pineapple pieces, cheese, and red onion. Top with top buns, brush with melted butter and garnish with reserved cilantro. Bake until buns are golden and cheese is melty, 10 to 15 minutes.