I cant find the setting to make the menu dropdown to show all at once or grouped way of showing…it depends on the template, but isnt there an easy setting to change it?
Sorry for the late reply.
Do you mean to show as mega menu? If so, just go to Appearance > Menus, find your menu. At the menu item you want to use as mega menu column, check the “Use as mega menu” check box. Then add as many items as you want to this column.
Let us know.