Hello,
Use the below code in UDF and pass the "MyFileName" value in target field.
DynamicConfiguration dynamicconfiguration = (DynamicConfiguration)param.get("DynamicConfiguration");
DynamicConfigurationKey key = DynamicConfigurationKey.create("http://sap.com/xi/XI/System/File", "FileName");
String MyFileName = dynamicconfiguration.get(key);
Regards,
Manigandan