JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://getbootstrap.com/dist/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="http://getbootstrap.com/dist/js/bootstrap.min.js"></script>
<ul class="nav">    
  <li id="js-navsection-1" class="dropdown"></li>
  <li id="js-navsection-2" class="dropdown"></li>
  <li id="js-navsection-3" class="dropdown"></li>
  <li id="js-navsection-4" class="dropdown"></li>
  <li id="js-navsection-5" class="dropdown"></li>
  <li id="js-navsection-6" class="dropdown"></li>
  <li id="js-navsection-7" class="dropdown"></li>
  <li id="js-navsection-8" class="dropdown">
    <a href="#" class="dropdown-toggle" data-toggle="dropdown" data-sectioncount="8">Conf</a>
    <ul class="dropdown-menu js-dropdown-nav" style="">
      <li id="js-ebizfields"><a href="">Test</a></li>
      <li id="js-clearcache"><a href="">Test</a></li>
      <li id="js-listebiz"><a href="">Test</a></li>
      <li id="js-catfields"><a href="">Test</a></li>
      <li id=""><a href="">Test</a></li>
      <li id="js-ctrylistcx"><a href="">Test</a></li>
      <li id="js-confcur"><a href="">Test</a></li>
      <li id="js-langedit"><a href="">Test</a></li>
      <li id="js-listlayo"><a href="">Test</a></li>
      <li id="js-ipman"><a href="">Test</a></li>
      <li id="js-log_level_token"><a href="">Test</a></li>
      <li id="js-orderchannel_config"><a href="">Test</a></li>
      <li id="js-orderfields"><a href="">Test</a></li>
      <li id="js-orderitemfields"><a href="">Test</a></li>
      <li id="js-pcatfields"><a href="">Test</a></li>
      <li id="js-paymentmenu"><a href="">Test</a></li>
      <li id="js-paymentmenu"><a href="">Test</a></li>
      <li id="js-platformapp_config"><a href="">Test</a></li>
      <li id="js-listplugin"><a href="">Test</a></li>
      <li id="js-complexapp_config"><a href="">Test</a></li>
      <li id="js-recurringlist"><a href="">Test</a></li>
      <li id="js-regnlist"><a...

CSS

ul.nav li.dropdown:hover ul.dropdown-menu{
    display: block;
}

.dropdown-menu {
    //max-height:400px;
    overflow-y:auto;    
}


ul.nav li:nth-child(8) ul.dropdown-menu li:nth-child(even) {
  margin: -26px 0px -24px 215px;
}

ul.nav li:nth-child(8) ul.dropdown-menu li:nth-child(odd) {
  margin: 24px 0px 0px 0px;
}

ul.nav li:nth-child(8) ul.dropdown-menu li:first-child {
  margin: 0;
}