Complex sentence: After his retirement, Bosz started a managing career, becoming first head coach of amateurs AGOVV Apeldoorn, a position he held from January 2000 to 2002; in 2002 he also won a national amateur league title.
Split into simpler sentences: After his retirement, Bosz started a career in management, first becoming head coach of amateurs AGOVV Apeldoorn, a position he held from January 2000 to 2002. In 2002 he also won a national amateur league title.