In a large mixing bowl, combine the cooked chicken, black beans, corn, red bell pepper, cherry tomatoes, avocado, red onion, and cilantro. Gently toss to mix the ingredients evenly.
In a separate small bowl, whisk together the Greek yogurt, mayonnaise, lime juice, chili powder, cumin, salt, and pepper until smooth.
Pour the dressing over the chicken mixture and toss gently until everything is well coated.
Taste and adjust seasoning if necessary. If you prefer a creamier salad, add more Greek yogurt or mayonnaise to your liking.
Chill the salad in the refrigerator for at least 30 minutes to allow the flavors to meld.
Serve cold, either on its own or over a bed of greens.