With a goal of improving operational efficiencies and adding more patient parking, a group of surgeons in Amherst is planning to nearly double the size of its surgery center at a new $4.75 million facility a mile away. Ambulatory Surgery Center of Western New York LLC has filed plans with the state to move its existing facility at Sheridan Drive and Alberta across from Northtown Plaza to Sweet Home Road, where it plans to build a 30,000-square-foot center on a 13.3-acre parcel. The surgery group…