Preheat the grill to medium heat. Season the skinless chicken breasts with some salt and pepper on both sides. Cook chicken for about 4 to 6 minutes on each side (until cooked thoroughly through). Baste the cooked chicken breasts with ¼ cup of BBQ sauce. Remove from grill and set aside for 3 to 4 minutes. Cut into bite-sized pieces.
Heat olive oil in a medium skillet over medium heat. Add corn and roast until slightly browned. Remove from heat.
Layer lettuce, tortilla chips, black beans, corn, tomato and cheddar cheese in a large salad bowl. Place grilled chicken on top. Drizzle with Ranch dressing and remaining BBQ sauce.