Complex sentence: In 2000, a compilation of unreleased "Anima Animus"-era tracks was released as "U.S. Retrace": it featured the b-side "All She Could Ask For" which was the opening number of all their concerts during that period.
Split into simpler sentences: In 2000, a compilation of unreleased "Anima Animus"-era tracks was released as "U.S. Retrace". It featured the B-side "All She Could Ask For", which was the opening number for all their concerts during that period.