What is "Savila Se Bela Losa"?
It is a Serbian Line dance.
Folk Music and Dance is still a strong force eastern Europe. Much television time is devoted to it.
From what I can tell it is a traditional Folk dance, meaning pre 19th Century when traditional Folk dancing went out of fashion. There is words about grape vines intertwining and then they become intertwining lovers. There is no indication of the origin of the words.
The dance is easy and starts in a circle then becomes a line dance.
Many Serbian dances are circle dances or "Kolo".
Serbia existed from the 9th century and folk dances could have developed any time since.