Heat gas or charcoal grill. Coat chicken breasts with taco seasoning mix; place on grill over medium heat. Cover; cook 6 to 8 minutes, turning once, until juice of chicken is clear when center of thickest part is cut (at least 165°F). Cut each chicken breast in half crosswise.
Top each chicken piece with cheese slice; cook 1 minute longer or until cheese is melted. Keep warm.
Reduce heat to medium-low. Separate dough into 8 biscuits. Spray both sides of biscuits with cooking spray. Place biscuits on double thickness of heavy-duty foil, about 3 inches apart. Place foil on grill over indirect heat; cover. Cook 4 minutes; turn. Cook 3 to 4 minutes longer or until golden brown.
Split biscuits in half. Place chicken on one half of each biscuit; top with guacamole and remaining biscuit half.