Bishop has one group to divide (6)
I believe the answer is:
bisect
'divide' is the definition.
(I've seen this in another clue)
'bishop has one group' is the wordplay.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'has' says to put letters next to each other.
'one' becomes 'i' (Roman numeral).
'group' becomes 'sect' (I've seen this in other clues).
'b'+'i'+'sect'='BISECT'
'to' is the link.
(Other definitions for bisect that I've seen before include "cross" , "create schism?" , "Divide into two equal parts" , "Cut twenty [IN TWO]" , "Cut in half" .)