JSFiddle - React, Tailwind, and code Playground

HTML

<div class="selectedText"></div>
<ul>
  <li>First level text
    <ul>
      <li>Second level text</li>
    </ul>
  </li>
 </ul>

JavaScript

var str = document.querySelector("ul li:first-child").firstChild.data;

console.log(str);