Complex sentence: Filin started dancing at age seven at the children's ensemble V. Lokteva in folk dances, where he appeared with Oleg Popov in the film "The Sun in the Bag".
Split into simpler sentences: Filin started dancing at age seven at the children's ensemble V. Lokteva of folk dances. At this time, he appeared with Oleg Popov in the film "The Sun in the Bag".