Complex sentence: Back at CIA headquarters, then located in Washington near the Lincoln Memorial, de Silva briefly worked in the "Foreign Intelligence Staff" under Eric Timm, before being appointed chief of operations in the "Soviet Russia Division".
Split into simpler sentences: Back at CIA headquarters, then located in Washington near the Lincoln Memorial, de Silva briefly worked in the "Foreign Intelligence Staff" under Eric Timm. Then he was appointed chief of operations in the "Soviet Russia Division".