How to set the width of the top level menu items?

Dear Cedric,
Is it possible to make second column contain two columns inside of it?
Please see file atatched:
I'd like to make block 3 next to the block 2 and under the block 1.
Because when I make block 3 start a new column inline it goes down and to the left border of the submenu.

not sure, because this is a bit special. Try to create all the columns, give them the width but don't use the option "return to the line", and give the submenu width in the parent item params
CEd

Thank you!
One more question if you don't mind
I've got some strange behaviour of the hover background color in the last column of the menu - it shows outside of the menu as well as the separators bottom border. Could you please take a look?
dovkillia.in.ua

this is because you have set a "100px" width for the submenu in the parent item params. Delete it and it should work

Thank you! That was it! Great!