The dropdown buttons can be duplicated if more dropdowns are necessary. The menu has been made sticky, so that it is always visible when scrolling the page. And any butten can be switched around to a different position. Also the sub-nav buttons can be duplicated.
The best thing is first to add this as a theme, and then select the top row and then create a component of it. But make sure not to overlook the bit of styling in the settings. Select the top row to create a component with this menu.