- var_dump: documentation ( source)
<?php
$xml = <<<'EOT'
<data>
<categories>
<categories_name>Toners</categories_name>
<childs>
<categories>
<categories_name>Ex ample</categories_name>
</categories>
</childs>
</categories>
</data>
EOT;
$doc = new DOMDocument();
$doc->loadXML($xml);
$xpath = new DOMXPath($doc);
foreach($xpath->query('//categories[child::categories_name="Toners"]/childs/categories[child::categories_name="Ex ample"]') as $node)
{
var_dump($node);
}