Untitled

<div>
  div text
  <div>div text</div>
</div>
outer text 1
<p>p text</p>
outer text 2

<div>
  div text
  <div>div text</div>
</div>
<p>p text</p>

$html = str_get_html("<body>$txt</body>");
$items = $html->find("body > *");

$result = "";

foreach($items as $item) $result .= $item;

print $result;