JSFiddle - React, Tailwind, and code Playground
HTML
<div class="post-outer" id="001">
<div class="post-footer">
<div class="post-outer">
<div class="post-footer-line post-footer-line-2">
<div class="post-labels"> <a href="label/teste2" rel="tag">tag1</a> </div>
</div>
</div>
</div>
</div>
<div class="post-outer" id="002">
<div class="post-footer">
<div class="post-outer">
<div class="post-footer-line post-footer-line-2">
<div class="post-labels"> <a href="label/tag2" rel="tag">tag2</a> </div>
</div>
</div>
</div>
</div>
<div class="post-outer" id="003">
<div class="post-footer">
<div class="post-outer">
<div class="post-footer-line post-footer-line-2">
<div class="post-labels"> <a href="label/tag3" rel="tag">tag3</a> </div>
</div>
</div>
</div>
</div>
<div class="result">
</div>
JavaScript
$('.post-outer .post-footer .post-footer-line.post-footer-line-2 .post-labels a').each(function(index, el) {
$(this).parents('.post-outer:eq(0)').attr('itemtype', $(this).attr('href') );
});