You can flush data to an XML target at each commit point in a session. However, each input group must receive data from the same transaction control point in the mapping. When you create a session based on this mapping, you can append data to the XML file target at each commit or create a new file at each commit. You can specify either option with the On Commit target property.
When you connect the XML target input groups to multiple transaction control points, the Integration Service writes the data to the XML file target after it processes all source rows.