In medium bowl, toss together chicken, 2 tablespoons lemon juice, 2 tablespoons olive oil and 2 teaspoons Sazonador; cover and refrigerate for about 10 minutes. In separate large bowl, toss together squash, onions, 2 tablespoons olive oil and 1 teaspoon Sazonador; set aside.
Meanwhile, place pasta in large bowl and toss with ¼ cup lemon juice.; set aside. In small bowl, whisk together remaining ⅓ cup lemon juice, ⅓ cup olive oil and ½ tsp. Sazonador; set aside.
Heat grill to medium heat. Place chicken, squash, onions and asparagus on hot grill grates. Grill chicken, flipping once, until juices run clear, about 12 minutes. Grill vegetables, flipping occasionally, until just tender, about 10 minutes. Transfer chicken and vegetables to cutting board until cool enough to handle. Cut vegetables into 1” pieces and slice chicken.
To reserved bowl with pasta and lemon juice, add chopped vegetables, sliced chicken, reserved olive oil mixture, pimientos, olives, tomatoes and basil; toss until evenly coated. Serve pasta salad at room temperature or chilled.