custom_navbar.js

$(document).ready(function () {

  $('.nestedmenu').on('click', function (e) {
  e.preventDefault();

  var url = $(this).attr('href');

  window.open(url, '_blank');

  });
  
    $('.navbar .dropdown-item').on('click', function (e) {
        var $el = $(this).children('.dropdown-toggle');
        var $parent = $el.offsetParent(".dropdown-menu");
        $(this).parent("li").toggleClass('open');

        if (!$parent.parent().hasClass('navbar-nav')) {
            if ($parent.hasClass('show')) {
                $parent.removeClass('show');
                $el.next().removeClass('show');
                $el.next().css({"top": -999, "left": -999});
            } else {
                $parent.parent().find('.show').removeClass('show');
                $parent.addClass('show');
                $el.next().addClass('show');
                $el.next().css({"top": $el[0].offsetTop, "left": $parent.outerWidth() - 4});
            }
            e.preventDefault();
            e.stopPropagation();
        }
    });

    $('.navbar .dropdown').on('hidden.bs.dropdown', function () {
        $(this).find('li.dropdown').removeClass('show open');
        $(this).find('ul.dropdown-menu').removeClass('show open');
    });

});