JSFiddle - React, Tailwind, and code Playground

HTML

<div class="focus">
  <div class="focus_col">COL1</div>
  <div class="focus_hidden">HIDDEN1</div>
</div>
<div class="focus">
  <div class="focus_col">COL2</div>
  <div class="focus_hidden">HIDDEN2</div>
</div>

JavaScript

$('.focus_hidden').hide();
$('.focus_col').hover(function() {
  $(this).find('.focus_hidden').slideToggle();
  return false;
});