Place chicken in bottom of crockpot. Pour entire bottle of parmesan garlic sauce over chicken. Fill sauce bottle with milk and shake; add milk to crockpot. Add cream cheese and parmesan cheese. Stir everything together to combine and coat chicken.
Cook on low for 3–4 hours or high for 2–3 hours.
Cook pasta according to package.
Shred chicken with two forks. Mix into sauce. Pour pasta into crockpot and stir to combine.