JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="//netdna.bootstrapcdn.com/twitter-bootstrap/2.2.1/css/bootstrap-combined.min.css">
<script src="//netdna.bootstrapcdn.com/twitter-bootstrap/2.2.1/js/bootstrap.min.js"></script>
<div class="dropdown">
  <a class="dropdown-toggle" data-toggle="dropdown" href="#">Dropdown trigger</a>
  <div class="dropdown-menu" role="menu">
      <ul>
          <ul>one</ul>
          <li>one</li>
          <li>two</li>
          <li>three</li>
          <li>four</li>
      </ul>
      <ul>
          <li>blah</li>
          <li>blah blah</li>
          <li>blah blah blah</li>
      </ul>
  </div>
</div>

CSS

.dropdown-menu ul {
    float: left;
}

.dropdown-menu ul:first-of-type {
    border-right: 1px solid black;
    padding-right:20px
}