JSFiddle - React, Tailwind, and code Playground

HTML

<div id ="one" class="block"><a href="">one</a></div>
<div id="thisdiv">hello</div>
<div id ="two"class="block">two</div>
<div id ="three"class="block">three</div>

CSS

#thisdiv {padding:10px; margin:-15px 0 0 40px; background-color:#333; position:absolute; display:none;}
div.block {margin-top:10px; width:200px;}
div#thisdiv a {color:#fff;}

JavaScript

$(document).ready(function() {
  $('#one').mouseover(function() {
   $('#thisdiv').fadeIn(400);
  });

  $('div:not(#thisdiv)').mouseleave(function() {
   $('#thisdiv').fadeOut(400)
  });
});