Complex sentence: Many young and sometimes amateur artists were invited to the group by fellow filmmakers, most notably Béla Tarr, who made his debut film at the age of 22 with financing from the Béla Balázs Studios.
Split into simpler sentences: Many young and sometimes amateur artists were invited to the group by fellow filmmakers. The most famous example for this is Béla Tarr who made his debut film at the age of 22 financed by Béla Balázs Studios.