Referencing ancestor nodes in an XML datasource

[garry_3]

The documentaion on XML datasources says:

To move to the parent value of the current node (for example, to determine the category to which a person belongs), use a slightly different syntax:

ancestor::category/@name

The ancestor keyword indicates that you are referring to a parent node of the current node;

A simplified example of the data is as follows:

<data>  <meta>    <unrelated>      <id>18</id>      <description>description</description>      <year>2014</year>      <code>2014GBN</code>    </unrelated>    <different>      <id>3</id>      <label>My label</label>    </different>  </meta>  <person>    <id>1308</id>    <code>Amj/3177</code>    <surname>Amj</surname>    <firstname>Jbswjt</firstname>    <middlename>Pbvm</middlename>    <gender>m</gender>    .....    <username>jbswjt/bmj</username>    <parent_node>      <id>1467</id>      <title>A title</title>      <priority>99</priority>      <code>09EN</subject_code>      <id>109</subject_id>      <description>English</subject_description>      <department_code>6</subject_department_code>      <node>        <id>39480</id>        <template_id>1</template_id>        <different_id>3</different_id>        <unrelated_id>18</unrelatedid>        ....      </node>    </parent_node>    <parent_node>      ....      <node>        ....      </node>    </parent_node>  </person></data>[/code]

How do you reference an element that is in an "unrelated" node?  i.e. how do I reference /data/meta/unrelated/code from node ?

The datasource for the subreport is:

<dataSourceExpression><![CDATA[((net.sf.jasperreports.engine.data.JRXmlDataSource)$P{REPORT_DATA_SOURCE}).subDataSource("person[id]/parent_node/node")]]></dataSourceExpression>[/code]

Any assistance would be greatly appreciated.