https://www.glass.org/themes/custom/nga_theme/dist/app-drupal/assets/megamenu-fix.js?tl447n

1const navSubmenu = document.querySelectorAll('.nav-submenu');
2const navSubmenuClose = document.querySelectorAll('.nav-submenu__close');
3const dropdownToggles = document.querySelectorAll('.navbar-nav .dropdown-toggle');
4let openMenu = -1;
5
6window.addEventListener('click', e=> {
7  if(e.target.closest('.nav-submenu') && !e.target.closest('.nav-submenu__close')) {
8    const menu = e.target.closest('.nav-submenu');
9    menu.classList.add('expanded');
10    menu.previousElementSibling.classList.add('expanded');
11  } else {
12    openMenu = -1;
13  }
14});
15
16navSubmenuClose.forEach(item => {
17  item.addEventListener('click', e => {
18    openMenu = -1;
19  });
20});
21
22dropdownToggles.forEach((el,i) => {
23  el.addEventListener('click', e => {
24    openMenu = i;
25  });
26});
27
28window.oncontextmenu = e => {
29  if(openMenu !== -1) {
30    const menu = navSubmenu[openMenu];
31    menu.classList.add('expanded');
32    menu.previousElementSibling.classList.add('expanded');
33  }
34}