Transfer of diamonds in German city (4,4)
I believe the answer is:
hand over
'transfer' is the definition.
(thesaurus)
'diamonds in german city' is the wordplay.
'diamonds' becomes 'd' (abbreviation in bridge say).
'in' indicates putting letters inside.
'german city' becomes 'hanover' (I've seen this before**).
'd' placed inside 'hanover' is 'HAND OVER'.
'of' acts as a link.
(Other definitions for hand over that I've seen before include "Present or give to another person - manually?" , "Pass across; surrender" , "Yield possession of in overhand way" , "Deliver into control of another - in manual way?" , "Pass something to control of another - manually?" .)