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]
(..) Go now! - No! Take these steps. Go. Help me. - l got you. Come on. Grab the chain. Grab it! Grab it! Go! Mom! Come on! Call to John. No. I know this hurts. (..)1991 Terminator 2: Judgment Day