In your slow cooker, add the chicken thighs, barbecue sauce, 1 jalapeño pepper, garlic, zest and juice from one lime, zest and juice from one orange, cumin, and salt and black pepper to taste. Cook on high for 4 hours or low for 6-8 hour or until the chicken is tender and shreds apart easily. Shred the chicken with two forks and keep the slow cooker set to warm while you prepare your other ingredients.
In a medium bowl, add the tomatoes, mango, pineapple, red onion, green onion, lime juice, remaining jalapeño, cilantro, and salt. Stir until thoroughly combined. Set aside.
Assemble your tacos by layering mashed avocado, barbecue chicken, salsa, red cabbage, sour cream, and cilantro on a charred tortilla.