Navigation menu with wp_nav_menu() and current-menu-item class question

I´m developing a theme wich has a navigation menu with 2 maybe 3 levels of deep. I´m using the current-menu-item class to style the selected option, but I would like this class to be applied only in the top-level of the menu list, not the inferior ones.

This way, a user would hover over a dropdown menu, pick the desired option, and the chosen option in the menu bar would change according to the css, not the chosen dropdown menu option.

Is there any way to do this?