While working on a Client site recently it became apparent we needed to make the top level Parent link not go anywhere. As an example if you have a menu item named Products, and under it you have 10 product pages you may want that top item not to be active.
There are several plugins you can install that will do different things with these links, however, the simpliest method is to apply a # to the link. From the Admin sidebar, select Menus. Under Custom Links insert a # in the URL, and give the menu item a Label. Add the custom menu item to the menu and then place your children links under it.
Now from any page the Top item will have a link, but it will simply stay on the current page.