JSFiddle - React, Tailwind, and code Playground

HTML

<div class="top">top
    <div class="middle">middle
        <div class="bottom">bottom</div>middle</div>top</div>
<div class="middle">outside middle</div>

CSS

*{padding:20px;}

.top{background:red;}
.middle{background:white;}
.bottom{background:blue;}

.green{color:green; font-size:120%;font-weight:bold;}

JavaScript

$top = $('.top');

$($top + ' .middle').click(function () {
    $(this).toggleClass('green');
});