A German pursuing extremely rich banker locally (5)
I believe the answer is:
rhein
'banker locally' is the definition.
I can't tell whether this defines the answer.
'a german pursuing extremely rich' is the wordplay.
'a german' becomes 'ein' ('a' in German).
'pursuing' says to put letters next to each other.
'extremely' suggests removing the centre.
'rich' with its centre taken out is 'rh'.
'ein' put after 'rh' is 'RHEIN'.
(Other definitions for rhein that I've seen before include "In Germany, find her in the river, strangely" , "(German name for) German river" , "Locally busy European river" , "You might find her in the river, strangely" .)