Complex sentence: They also appeared in the Croatian Cup five times between 1998 and 2002 and their best result was reaching the cup quarter-finals in the 2001--02 season where they were knocked out by NK Osijek 5--0 on aggregate.
Split into simpler sentences: They also appeared in the Croatian Cup five times between 1998 and 2002. Their best cup result was reaching the quarter-finals in the 2001--02 season where they were knocked out by NK Osijek 5--0 on aggregate.