Complex sentence: Shortly after returning to action from a repair in the USA, after an attack by an E-Boat in her Mediterranean deployment, she was attached to the Eastern Fleet at Ceylon, acting as the lead ship of the Fourth Cruiser Squadron.
Split into simpler sentences: Shortly after returning to action from a repair in the USA, she was attacked by an E-Boat in the Mediterranean. She was then attached to the Eastern Fleet at Ceylon, acting as the lead ship of the Fourth Cruiser Squadron.