2nd level sub navigation

hi there

i am creating a site with what should be a simple menu

it looks like this

Main menu item (drop down)
-Category (not clickable)
-sub category (sub item but must be under the category not a fly out)
and then i need columns too

example is here http://www.tohaveandtohold.co.za/

i have been playing around and seem to have got the first piece right – but can not get the columns to work – is there a short code for this?

please let me know

https://ww.wp.xz.cn/plugins/bootstrap-3-shortcodes/

https://ww.wp.xz.cn/plugins/megamenu/