将鼠标悬停在父级或菜单上时，保持弹出菜单打开

I've been through quite a few questions on here trying to figure out the best way to do this but can't make them work with my code. I just want the flyout menu to stay put while the mouse is on it after becoming visible when the main menu item element is hovered. Note that the sub-menus are I've been through quite a few questions on here