Also known as “CoC”, the chain of command essentially means that if you have any requests, questions, problems or concerns you should Contact Your Squad Leader first.
Outside of the squad hierarchy, the Squad Leaders move paperwork up to the platoon Sergeant who would bring it to the platoon Leader. From the platoon level the Platoon Sergeant will take issues he has to the Company Sergeant and the Platoon leader will take issues he has to the Company Commander.
Everything, both positive and negative, moves from the bottom up and from the top down. It is important that avoid skipping steps in the chain of command when ever your issue can be dealt with by your immediate superior.