Complex sentence: Van Dijk retired in 1992, and became a football manager, who coached FC Groningen, Roda JC, RBC Roosendaal, Helmond Sport and FC Emmen.
Split into simpler sentences: Van Dijk retired in 1992, then became a football manager. He coached FC Groningen, Roda JC, RBC Roosendaal, Helmond Sport, and FC Emmen.