How to point parent menu item to a link and sub menus too
You can do this by using below modules :


Path Breadcrumb



  This module is a solution for all problems with the breadcrumbs on
  your site!
  
  Path Breadcrumbs module helps you to create breadcrumbs for any page
  with any selection rules and load any entity from the URL!



Menu Breadcrumb



  By default, Drupal 6+ use the Navigation menu for the breadcrumb. This
  module allows you to use the menu the current page belongs to for the
  breadcrumb.