Add chicken and 1/3 cup bbq sauce to a ziplock bag. Refrigerate for 1-3 hours.
Make the creamy cilantro lime sauce by combining all ingredients until smooth. Refrigerate until ready to serve.
Preheat grill and lightly grease with cooking spray. Add chicken and cook for 4-5 minutes on each side, flipping once, until cooked through (165 degrees F). Remove to a cutting board, baste with more BBQ sauce, and allow to rest for 5 minutes before chopping.
Warm tortillas on grill or in a hot skillet. Add a spoonful of chopped chicken, corn, black beans, tomatoes and avocado to each warm tortilla. Drizzle with extra bbq sauce, and cilantro lime sauce. Garnish with fresh cilantro. Enjoy!