Multi-level navigation and easy menu definition

[mvlcek]

I've sent you all info in PM.

Below image shows the problem.
On the left is the menu currently rendered.
On the right is the submenu's functionality I'd like to get.

First: you write sibling, but according to the pictures and description you seem to mean child.
It's not the siblings (i.e. same level), but children (i.e. level below) that is/should be displayed.

The left version in the image is only displayed, if you use I18N_SHOW_MENU or I18N_SHOW_PAGE as 4th parameter - you need to use no 4th parameter or set it to I18N_SHOW_NORMAL.

I18N_SHOW_MENU means: show the whole menu independent of the current active page.