Place the chicken breasts in the crockpot. Add butter, cream of chicken soups, chicken broth, onion and salt & pepper. Cook on low for 8 hours or high for 4 hours. Remove chicken breasts from the crockpot and shred them. Once shredded, return the chicken to the crockpot. Cut up biscuits into small 1-inch pieces and add them to the pot. Cook an additional 30 minutes on high. Serve hot.