JSFiddle - React, Tailwind, and code Playground
HTML
<div class="sidebarmenu">
my div
<ul>
<li>......</li>
<li>......</li>
</ul>
</div>
JavaScript
$(".sidebarmenu").mouseenter(function(){
$(this).find('ul').show('slow');
});
$(".sidebarmenu").mouseleave(function(){
$(this).find('ul').hide('slow');
});