Are you trying to set the value in the output response. If so, click on TREE view button, next click on web service call function in the left panel. On right hand side you will see snapshot tab, click on that to view snapshots of request and output response. Right click on the child node for which you want to set the value. A popup window appears, click on insert xml check. XML check properties window appears there you can find XPath Query value. Use that value in your lr_xml_set_values function.
If the above does not work, try like this "Query=/address1",
Does this helps you.