Complex sentence: On 2 April 1917 Weston was posted to No.2 Wing RNAS at Mudros, on the Greek island of Lemnos, again as compass officer which had been an important military base during the Gallipoli campaign but was now being used to support other cpaigns against the Ottoman Empire.
Split into simpler sentences: On 2 April 1917 Weston was posted to No.2 Wing RNAS at Moudros on the Greek island of Lemnos, again as compass officer. Moudros had been an important military base during the Gallipoli campaign but was now being used to support other cpaigns against the Ottoman Empire.