Don't think Tilston St Mary has been indexed as yet for births or deaths, but when it is there are various districts for it depending on the year that you are looking for. It has been indexed for marriages 1837-1950
Great Boughton (1837-69), Chester (1870-1937), West Cheshire (1937-74), Chester and Ellesmere Port (1974-98), Cheshire West (1998 to present) All the records would now show under Cheshire West.