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Multi level menu columns

It is currently not possible since that is a multi level menu. 

It is not recommended to use that kind of menu if you have too many second level items like this

Any one of those items can potentially have additional 3rd level sub-sub-menus so that is the principle on which the menu works, but each level should have no more than 10 items so it can extend laterally.

Maybe you can use a different menu type, try the "Mega Menu" dropdown, which is just a page builder essentially and you can add other menu modules in it, like the Catalog menu module from Journal > Modules > Catalog Menu... This module supports columns in auto grid mode, each column is a category which displays sub-sub categories as links.