Participants in range (5)
I believe the answer is:
field
I believe this is a double definition.
'participants' is the first definition.
(eg the field of job applicants)
'range' is the second definition.
(thesaurus)
'in' is the link.
(Other definitions for field that I've seen before include "Line of business - enclosed farm area" , "Domain" , "Pitch" , "The ... (John B Keane)" , "Branch of study" .)