PHP function to edit HTML using php DOM Parser

In a page I need to find a text or a HTML element by class. If I find this text (or element), in the page I show or hide specific div.classes.

HTML:

<!-- If found -->
<div class="x">content</div> <!-- hide -->
<div class="y">content</div> <!-- hide -->
<div class="z">content</div> <!-- show -->
<div class="w">content</div> <!-- show -->

<!-- If NOT found -->
<div class="x">content</div> <!-- show -->
<div class="y">content</div> <!-- show -->
<div class="z">content</div> <!-- hide -->
<div class="w">content</div> <!-- hide -->

I would use a php function in functions.php to do this, because I already use js but it works badly.

You can see a method to filter data like this (ref. here):

<?php
require_once('simple_html_dom.php');

function page_filter($content){

    // Only proceed if we're using the right template
    $template = get_post_meta(get_the_ID(), '_wp_page_template', true);
    if ($template != 'main-template.php'){
        return $content;
    }

    // Re-generate DOM after stripping p tags off images
    $html = str_get_html(strip_p_from_img($content));

    // p tags and anything that can interrupt them
    $replace = "p,h1,h2,h3,h4,h5,h6,img,hr,table"; 

    // For looping purposes.
    // Are we currently in a div?
    $mid_div = false;

    // Get all instances of tags in $replace
    $instances = $html->find($replace);

    // loop through
    foreach ($instances as $key=>$element){
        $tag = $element->tag; // get current tag

        // If we aren't mid-div and encounter a paragraph, start our div!
        if (!$mid_div){  
            if ($tag === 'p'){
                $instances[$key]->outertext =
                "<div class="long-description">" . $element->outertext;
                $mid_div = true;
            }

            // This is a limiting case; the only tag is a single paragraph
            if (!array_key_exists($key+1, $instances)){
                    $element->outertext .= "</div>";
                }
            else{
                $mid_div = true; // we're mid-div now!
            }
        }

        // If we're mid-div and hit an "interrupting" tag, 
        // or we're out of paragraphs, end the div!
        else{
            if ($tag !== 'p'){
                $element->outertext = "</div>" . $element->outertext;
                $mid_div = false;
            }
            if ($tag === 'p' && !array_key_exists($key+1, $instances)){
                $element->outertext .= "</div>";
                $mid_div = false;
            }
        }
    }
    
    return $html;
}
add_filter('the_content', 'page_filter');

Can I edit the above function for my needs? Thank you.