I have the following structure (defined at Appearance > Menu):
Now, in my theme I have one horizontal menu that shall always display
foo | bar
Below that, there's another horizontal menu which, when foo is clicked, should display:
fii | faa | fee
When bar is clicked, that same menu shall display:
boo | bee | bii
Only the sub-menus of the currently selected main menu (foo/bar) shall be displayed.
How can this be achieved?