Complex sentence: That season was used to qualify clubs for participation in the Gauliga Sudetenland (I) as the regime forced the merger of existing clubs into new sports associations each known as Nationalsozialistische Turngemeinde (National Socialist Gymnastics Community).
Split into simpler sentences: That season was used to qualify clubs for participation in the Gauliga Sudetenland (I). The regime subsequently forced the merger of existing clubs into new sports associations each known as Nationalsozialistische Turngemeinde (National Socialist Gymnastics Community).