Interface Configuration Issue

Hi,

I am using XI 3.0 and in the process of configuring an interface which works like:

Idoc -

>maps to --> Custom_Invoice --> result( Custome_Invoice with output1) - First Layer

Custome_Invoice with Output1 --> maps to --> xCBL Structure --> result(xCBL Envelope with Output 2) - Second Layer

In the Integration Builder (Design) I have designed the Interface mapping from Idoc to Custome_Invoice and

Custom_Invoice to xCBL structure.

How can I group these components (Idoc, Custome_Invoice and xCBL) together using either BPM or some

other way? Particularly how can I capture the output1 and pass on to the input for the Second layer processing.

Any idea or suggestion how I can achieve this pls.

TIA.

Cheers,

Ranjan