Challenge for a menu layout

[rodeto]

Right now my menu looks like this
1: Home
2: Algemeen
3: Activiteiten
3.1: Wandel- en fietstours
3.2: Bedrijfsuitjes
3.3: Teambuilding
3.4: Workshops

pages 3.1 till 3.4 all have more subpages.

What I would like to have is that when I click on page 3.1 (or 3.2, 3.3, 3.4) only the children of that particular page apear and that the other subpages ( 3.2, 3.3, 3.4) disappear. Whn I click on page 3 again, the subpages can appear again without their children.

I have no idea if this is possible or how to make this possible. I have been trying to get it working but no luck so far.

What I use right now is the simple_navigation.tpl in the menumanager with some minor adjustments. Everything has the latest releases.

Anyone who can sort out this challenge ?