Protesters formed 'a human chain' [=they stood next to each other with their arms linked] around the ancient tree to prevent it from being cut down.
In the United States, the President as the commander in chief is at the head of the military 'chain of command'.
I thought he really won the lottery but he was only 'pulling my chain'. [=he was only playing a joke on me]
(..) Quit stalling and move! - Mr. Taylor. - Wait a minute. Tell Senator Paine. About this Smith filibuster. Your chain of newspapers must realize that this bill he is trying to block - - will affect your section. It's the patriotic duty of every newspaper in the country! (..)1939 Mr. Smith Goes to Washington