<personDetails>
    <person>
        <name>Mr Test</name>
        <paid>Yes</paid>
        <details>
            <detail>
                <id>12345</id>
                <address>15 Sample Street</address>
            </detail>
        </details>
    </person>
</personDetails>

//personDetails/person[name='Mr Test'] and //personDetails/person/details/detail[id ='S0335171']/paid/text()

public String getPaidByNameAndId(String name, String id) {
        final String _Name = name;
        final String _id = id;
        return engine.new Query<String>(PERSON_COLLECTION) {

            @Override
            protected String query(Collection collection) throws Exception {
                XQueryService service = queryService();

                ResourceSet resourceSet = service.query(
                        format("//personDetails/person[name='%s'] and //personDetails/person/details/detail[id ='%s']" +
                                        "/paid/text()"
                                , StringEscapeUtils.escapeXml(_Name),
                                StringEscapeUtils.escapeXml(_id)
                        ));

                for (String resource : new IterableStringResources(resourceSet)) {
                    results.add(resource);
                }
                return results.get(0);
            }
        }.execute();
    }

org.exist.xmldb.XQueryService;