Complex sentence: In late 2004, the group announced that they would be going on a two-year hiatus and released their first compilation album, "Best of Blue" on 15 November 2004.
Split into simpler sentences: In late 2004, Blue announced that they would be going on a two-year hiatus. This coincided with the release of their first compilation album, "Best of Blue", released on 15 November 2004.