Context Mapping, flat file to deeply nested XML Structure

Hello,

I am trying to use Graphical mapping where my Source structure is

Records

             Record

             Batch_Header

             Detail

             Batch_Control_record

             Record_trailer

I want to map Detail section into a nested XML Structure(items) which is.

Main

     Batch

          Details

               Items

      Batch_trailer

file_trailer  

I am trying to do this using the graphical mapping, any suggestions ?