Drop down section

Is it possible to do a drop-down menu for the sections?
Like you click on one section and it drops down to the sub-sections you have in that section.

You can add the code for a drop down menu in the forum description box.

What will be the code for that, and where do I put it?

Are you want the drop down menu to the navbar?

Nope, I want a drop-down menu for the sections, not the navbar.

Bump, any solutions or is it physically impossible?