Item found in Boots by setter, with nothing to hide source of all ... (7)
I believe the answer is:
hobnail
'item found in boots' is the definition.
(nail in the sole of a boot)
I cannot understand how the rest of the clue works.
(Other definitions for hobnail that I've seen before include "One keeping shoes on" , "Stud for boots" , "Walk over roughly" , "Stud on boot" , "Protection for the sole of a heavy boot" .)