<?php

/*
<data>
<menu id="0" tpl="" name="Impressum" link="" target="" secure="">
        <site id="0" tpl="index" name="Datenschutz" link="" target="" secure=""/>
        <site id="1" tpl="index" name="Datenschutz" link="" target="" secure=""/>
        <site id="2" tpl="index" name="Datenschutz" link="" target="" secure=""/>
    <menu id="1" tpl="" name="Impressum" link="" target="" secure="">
            <site id="10" tpl="index" name="Datenschutz" link="" target="" secure=""/>
            <site id="11" tpl="index" name="Datenschutz" link="" target="" secure=""/>
            <site id="12" tpl="index" name="Datenschutz" link="" target="" secure=""/>
    </menu>
</menu>
</data>
*/
$doc = new DomDocument;

// We need to validate our document before refering to the id
$doc->validateOnParse = true;
$doc->load('php.xml');
//header('Content-Type: text/xml');
//echo $doc->saveXML();

$sites = $doc->getElementsByTagName('site'); // Find Sections
foreach ($sites as $site) //go to each section 1 by 1
{

    if($site->getAttribute('id') != '11')
        continue;

    echo $site->parentNode->getAttribute('id');
}