JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="uol">
      <li>beta</li>
      <li>gamma</li>
      <li>alpha</li>
    <li>beta</li>
    <li>zeta</li>
    <li>BETA</li>            
</ul>

<input type="button" value="Find" />
<input type="button" value="Remove" />

JavaScript

$('li', this)
.filter(function() {
// not sure what to do here?
.addClass('selecteditems');