Complex sentence: Sam Manekshaw (later a field marshal) was a colonel in the Directorate of Military Operations who went to Srinagar with V. P. Menon to assess the situation on 26 October 1947.
Split into simpler sentences: Sam Manekshaw (who later became Field Marshal) was a colonel in the Directorate of Military Operations. He went to Srinagar with V. P. Menon to get a first-hand assessment of the situation on 26 October 1947.