JSFiddle - React, Tailwind, and code Playground

HTML

<h1>Setup List</h1>
<ul>
	<li class="divider">Divider A </li>
	<li>Sub Text</li>
	<li class="mydivider">Sub Text</li>
	<li>Sub Text</li>
	<li class="divider">Divider B </li>
	<li>Sub Text</li>
	<li>Sub Text</li>
	<li>Sub Text</li>
	<li class="divider">Divider C </li>
	<li class="mydivider">Sub Text</li>
	<li>Sub Text</li>
	<li>Sub Text</li>
</ul>
<h1>Expected Result</h1>
<p>Divider A Divider C </p>
<h1>Actual Results</h1>
<p><strong><code>.prev()</code> Misconception</strong> - <span id="prev-result"></span></p>
<p><strong><code>.prevAll()</code> Workaround</strong> - <span id="prevAll-result"></span></p>
<p><strong><code>.prevFirst()</code> Solution</strong> - <span id="prevFirst-result"></span></p>

JavaScript

(function( $ ) {
	$.fn.nextFirst = function( type ) {
		return this.map(function() {
			return $(this).nextAll( type + ":first" );
		});
	};
	$.fn.prevFirst = function( type ) {
		return this.map(function() {
			return $(this).prevAll( type + ":first" );
		});
	}
})(jQuery);

$(function(){
	var	prevResult = $(".mydivider").prev(".divider"),
		prevAllResult = $(".mydivider").prevAll(".divider:first"),
		prevFirstResult = $(".mydivider").prevFirst(".divider");
	$("#prev-result").html(prevResult.text());
	$("#prevAll-result").html(prevAllResult.text());
	$("#prevFirst-result").html(prevFirstResult.text());
});