.tags li.hidden {
display: none;
}
document.querySelectorAll('.tags b').forEach(n => {
n.closest('li').classList.add('xxx');
n.addEventListener('click', onClick);
});
function onClick(e) {
for (
let el = e.target.closest('li');
(el = el.nextElementSibling) && !el.classList.contains('xxx');
el.classList.toggle('hidden')
) ;
}