Go to settings submenu item - customize main menu, in movies, press left arrow, in the first empty, replace with create video smart playlist in right list;
now go to
Create 2 smartplaylist, one for sd and other for hd. Use resolution in smartplaylist for it, with simple rule < 719 equal SD and >719 for HD.
Came back to customize main menu, hidden movies item, and create 2 new item in main menu in 2 empty fields, HD Movies and SD movies (use replace function), in right list use Choose Video Smartplaylist. Rename Items, and clone submenu movies.
Hidden movies item in main menu
cloning submenu for hd movies
result in
repeat steps for SD Movies
Done.