Complex sentence: However, they were demoted to the CBL again for the 1988 season after finishing last in 1987, but after winning the CBL championship in 1988, the team was back in the NBL again for the 1989 season.
Split into simpler sentences: However, they were demoted to the CBL again for the 1988 season after finishing last in 1987. After winning the CBL title in 1988, the team was back in the NBL for the 1989 season.