This hack is obsolete from V 4.2 and using this mod to extend the navigation manager:
https://vborg.vbsupport.ru/showthread.php?t=283123
To make sub-sections highlight their parent section, just multiple select the sub-sections and the parent section in the 'Sections' listbox when adding a new tab in the admin panel.
The code mods in my hack can be safely removed. The template mod in vbcms_navbar_link should be removed.
Thanks to the VB team and Andreas for a flexible navigation system and the extension. It is a real pleasure to see the end of my hack!