Answer
Germany and Spain served as the primary stage for Stielike's club career. In Germany, he left an indelible mark on the Bundesliga, showcasing his talents for Borussia Mönchengladbach. Notably, he played a pivotal role in their UEFA Cup triumph during the 1978-79 season. Stielike's journey then led him to Spain, where he joined Real Madrid and went on to become an integral part of their legendary team.