Anonymous,
This "stripping off" is called parsing, and the translator breaks the EDI document into each ST-SE as it transforms them from EDI to their XML representation.
You can select fields to carry across into "property bag", which goes along side each individual ST-SE transaction from the batch and it is available to allow the document to be "routed" via the publish-subscribe mechanism. So you make receive ports that subscribe to the flow of particular transactions on an arbitrary basis. These ports are then linked to maps.
– weak architect