Complex sentence: Frederick Spotts "Hitler and the Power of Aesthetics", p.291 Furtwängler was at that time decided, for the first time, to leave his country and to continue his career in Austria and Switzerland.
Split into simpler sentences: Frederick Spotts "Hitler and the Power of Aesthetics", p.291 Furtwängler was then decided for the first time to leave his country. He wanted to continue his career in Austria and Switzerland.