I'm currently very close to St Giles-in-the Fields and it's nowhere near Greenwich! St Giles is very central in London - the church still exists, very close to Centre Point.
A Clements Lane still exists a little bit east of here, in the City (near Monument) but St. Clements Lane really is close to here (Holborn/Kingsway area) and within the St Giles parish.
Hughes Fields doesn't ring any local bells with me, but there were lots of fields with grazing for livestock around here at that time (Lincoln's Inn Fields being the biggest which survives to this day as a square) so perhaps it was a small place which didn't make it into the directories.
HTH
Anna