JSFiddle - React, Tailwind, and code Playground

HTML

<div class="level1" data-attr="Level 1">Level 1
    <div class="level2" data-attr="Level 2">Level 2
        <div class="level3" data-attr="Level 3">Level 3
            <div id="starthere">HERE!</div>
        </div>
    </div>
    <div class="level2" data-attr="Level 2">Level 2</div>
</div>

JavaScript

jQuery.expr.match.closest = /^:(?:closest)$/;
     jQuery.expr.find.closest = function (match, context, isXML) {
         console.log("jQuery.expr.find.closest");
     };

     alert($('#starthere:closest(div)').data('attr'));