JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper" style="display:none">
          <div class="panel"></div>
        </div>

JavaScript

$.fn.custom = function() {  
        return this.each(function() {
           console.log(" this = ", this);
               // do something to each dom element.
        });
    };

var element = $(".wrapper");
element.toggle().children(":first").custom();
$(".wrapper .panel").custom();