Redirecting to a relative URL in JavaScript
You can do a relative redirect:
window.location.href = '../'; //one level upor
window.location.href = '/path'; //relative to domain
If you use location.hostname you will get your domain.com part. Then location.pathname will give you /path/folder. I would split location.pathname by / and reassemble the URL. But unless you need the querystring, you can just redirect to .. to go a directory above.
https://developer.mozilla.org/en-US/docs/Web/API/Location/assign
window.location.assign("../");// one level upwindow.location.assign("/path");// relative to domain