Is it possible to customize the SharePoint top navigation with fly-out menus that display sub-sites?
I was able to figure it out myself and here is the solution
Here is my Taxonomy | Canada | Ontario | Toronto | North York | When I move the mouse over to Canada, I want to see all the sub sites in flyouts menu
Now I am going make some changes to the master page to have four level flyouts. Open your SharePoint site using SharePoint designer 2010 and edit your master page
By default the Maximum Dynamic Display Level is 1 and I am going to change to 4
Now search for “topNavigationDelegate” and change the values to “True”
and remove "StartingNodeUrl="sid:1002"
Save your master page and publish. Make sure your sub sites SharePoint Server Publishing features are actives
This is the end result