JSFiddle - React, Tailwind, and code Playground

HTML

<div class = "row Parent">

<div class="col-md-8 ClildDiv1">

//Some Content

</div>

<div class="col-md-4 ChildDiv2">

//Some Content

<div>

</div>

CSS

.ChildDiv2 {
 display:none 
}

.ClildDiv1:hover ~ .ChildDiv2 {
  display: block;
}