JSFiddle - React, Tailwind, and code Playground
HTML
<div class="tree">
<div class="item">
<!-- replaced OK --> <a href="" class="toggle">+</a>
<a href="" class="name">Name</a>
<div class="collapse">
<div class="item">ghjghj
<!-- this wouldn't be replaced ?! -->
</div>
</div>
</div>
<div class="item"></div>
<!-- replaced OK -->
</div>
JavaScript
$('.tree').find($('.item')).each(function( index ) {
$(this).replaceWith($("<li>").append($(this).contents()));
});