Add 1 cup boiling water to lemon gelatin mix in medium bowl; stir 2 min. until completely dissolved. Cool slightly. Add cream cheese and marshmallows; beat with mixer on low speed until well blended. Refrigerate 1 hour or until slightly thickened.

Stir whipped topping, pineapple and nuts into lemon gelatin; pour into 4-qt. serving bowl. Refrigerate 1 hour or until set but not firm. Meanwhile, add remaining boiling water to cherry gelatin mixes in separate medium bowl; stir 2 min. until completely dissolved. Stir in cold water. Refrigerate 1 hour or until completely cooled.

Spoon cherry gelatin over lemon gelatin layer. Refrigerate 2 hours or until firm.