JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div>
        <div>
            <div>
                <span>
                    <a class="child">Child</a>
                </span>
            </div>
        </div>
    </div>
</div>

JavaScript

var parent = document.querySelector('.parent');

if (parent.querySelector('.child') !== null) {
    alert('It exists as a child.');
}