Where people are both in and out of capital? (11,4)
I believe the answer is:
stockbroker belt
'where people are both in and out' is the definition.
The definition suggests a singular noun which matches the answer.
'capital?' is the wordplay.
I cannot quite see how this works, but
'capital?' could be 'stock' (stock is a kind of capital) and 'stock' is located in the answer.
This explanation may well be incorrect...
'of' is the link.
(Other definitions for stockbroker belt that I've seen before include "in which you'll see people out of business?" , "part of Surrey?" , "wealthy area" , "Suburbia" , "Prosperous area" .)