Hey there,
what kind of dropdown-menu are you talking about? Do you mean a select-box, such as this one:
Or are you talking about a (bootstrap?) dropdown, as shown here: http://getbootstrap.com/components/#nav-dropdowns
The latter is easy, you can just add your desired pretty url to the <a>-Tag inside the dropdown.
For the first option, you'll need an event listener on that select-box, you can do so by using a can.control.
This event listener should then update the can.route according to the selected options.
Do you know how to use can.route?
Regards,
Fabian