I'm not sure this cemetery is extant.It is not listed in the Ohio cemetery index....only these, with that name; Greenbriar Cemetery Van Wert Greenbrier Cemetery Clermont Greenbrier Cemetery Pike Greenbrier-West Union Cemetery Carroll
There is one listed, with this name, on the GNIS mapping site, with long. and latit. ...if you have a GPS in your car, you could find it using these.
Greenbrier Cemetery Monroe OH (lat)393826N (long) 0810707W Antioch