There are plenty of examples show how to draw Venn diagrams using \clip command, such as https://texample.net/tikz/examples/set-operations-illustrated-with-venn-diagrams/
However, all those examples directly draw a circle or other shapes. I prefer to draw all the shapes via \node command, cause it is easy to place nodes using relative placement. I do not know how to use \clip command with \node command. Besides, the meaning of clip command is very hard to follow for me.
