Bishop, for one, whose position is determined by rank and file (8)
I believe the answer is:
chessman
'bishop' is the definition.
(bishop is an example)
'one whose position is determined by rank and file' is the wordplay.
I cannot really understand how this works, but
'one' could be 'an' (an apple is one apple) and 'an' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
Can you help me to learn more?
(Other definitions for chessman that I've seen before include "Eg, bishop or rook" , "Playing piece" , "Eg, bishop, knight" , "that's played on board" , "queen, perhaps" .)