Subtleties of French resort with connections (8)
I believe the answer is:
niceties
'subtleties' is the definition.
('nicety' can be a synonym of 'subtlety')
'french resort with connections' is the wordplay.
'french resort' becomes 'nice' (I've seen this before).
'with' means one lot of letters go next to another.
'connections' becomes 'ties' (tie is a kind of connection).
'nice'+'ties'='NICETIES'
'of' is the link.
(Other definitions for niceties that I've seen before include "Fine points" , "delicacies" , "Shades" , "Delicacy" , "Degrees of precision" .)