Add chicken, sausage, cream cheese, ranch seasoning, chicken broth, and pepper to the slow cooker.
Cover and cook on Low for 5-6 hours or High for 3 hours.
Shred the chicken in the pot and stir well.
Add macaroni, cheddar, and mozzarella; stir to combine.
Cover and cook on High for 25-30 minutes, until pasta is tender.
Stir once more and top with parsley before serving.