JSFiddle - React, Tailwind, and code Playground

HTML

<h3>A Heading</h3>
<p>Here is a paragraph.</p>

<ul>
  <li>First</li>
  <li>Second</li>
</ul>

<blockquote>Here's some other block-level element</blockquote>

<h3>The Wrapping Should Stop Before This Heading, but a Second One Should Begin</h3>
<ol>
  <li>First</li>
  <li>Second</li>
</ol>

<p>Notice the varying block-level elements? It probably doesn't make any difference.</p>

JavaScript

$('h3:first').nextUntil('h3').addBack().wrapAll('<div>');