Headers in Dynamic Dropdown Menu

Is there a way to add Headers within a dynamic dropdown menu?

Something like this:

Drop Menu
– Product Line 1 (header no link)
———-Listing 1 (with link)
———-Listing 2 (with link)
———-Listing 3 (with link)
– Product Line 2 (header no link)
———-Listing 1 (with link)