When we go on a page with a parent page invisible, the parent page reappear on menu.

For example, here the following sitemap:

• Section 1
  • Page 1
    • Page 11
  • Page 2 (invisible)
    • Page 21
    • Page 22

The Page 2 and its subpages are invisibles in menu except when we access to Page 21 or Page 22