JSFiddle - React, Tailwind, and code Playground
by Axiniya
HTML
<nav>
<ul>
<li>
<a href="#">Воторой уровень</a>
<div class="child-item">
<ul>
li
</ul>
</div>
</li>
<li></li>
<li></li>
<li></li>
</ul>
</nav>
CSS
.hoverable:not(:hover) + .show-on-hover {
display: none;
}