Complex sentence: Olimpija Ljubljana had a long tradition of playing in the Yugoslav first league and their squad was still composed of players from that era, dominated the league and won a further three championships before Gorica won their first in the 1995--96 season.
Split into simpler sentences: Olimpija Ljubljana had a long tradition of playing in the Yugoslav first league and their squad was still composed of players from that era. They dominated the league and won a further three championships before Gorica won their first in the 1995--96 season.