JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
  <!-- Lots of the following divs -->
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out stuff</div>
  </div>
  <div class="child">
    Text Line
    <div class="child-menu">some pop out...

CSS

.parent { overflow-y:scroll; width:100%; height:100px; }
.child { position:relative; }
.child .child-menu { position: absolute; left: 80px;width:200px; top:0px; border: 1px solid black; background-color: green; display: none; }
.child:hover .child-menu { display: block; }