Complex sentence: He was offered to move to Thessaloniki, where the headquarters of the Entente was locaded and to stand there to represent the interests of Bulgaria in the region of Macedonia to the victors in the war.
Split into simpler sentences: He was offered to move to Thessaloniki, where the headquarters of the Entente was locaded. He had to stand there wit aim to present the interests of Bulgaria to the victors in the war.