Thank you for the provided sample.
Actually the menu item is rather hidden by overflowing of the k-window-content
than hidden behind a div. There is no possibility to specify by CSS which children will be cut by parent's overflowing and which not. You can resolve the issue add a target that will replace the menu root item, and subitems will be actually context menu
. In this case context menu will be rendered as a popup outside window element so it will not be cut.