In 5- to 6-quart slow cooker, place chicken pieces. Spoon soup over chicken. Top with sweet potatoes. In medium bowl, mix stuffing mix, water and melted butter. Spoon over sweet potatoes.
Cover; cook on Low heat setting 4 to 6 hours.
About 20 minutes before serving, sprinkle green beans over stuffing. Cover; cook on Low heat setting 15 to 20 minutes longer or until beans are tender.