Dear Pankaj,
Login to the transaction SPROXY and you will see the below initial screen. ( Note : I have erased the client specific information ).
Expand the hierarchy on the left side highlighted in the above picture and you will be able to see the below set of components :
1) Datatypes 2) Messagetypes 3) Service Interfaces 4)Orphaned Objects.
The structure information in present in the Datatypes node. So expand it as below. 
On double clicking the node under Datatypes, you will be able to see the screen on the right hand side ( as shown in the above picture ). Click on the ABAP Name field ( highlighted in blue in the above picture ).
System takes you the structure of the proxy interface. Of this the CONTROLLER field is a default one and the remaining ones are part of the file.
Hope this helps.
Thanks.
With Regards,
Mohammed Muzammil.