This example creates a polygon with an inner hole, by defining an inner path wound in the opposite direction to the outer path. Note that you can also use the Data layer, which offers a simpler way of creating holes because it handles the order of the inner and outer paths for you.
Read the documentation.
Git and Node.js are required to run this sample locally. Follow these instructions to install Node.js and NPM. The following commands clone, install dependencies and start the sample application.
git clone -b sample-polygon-hole https://github.com/googlemaps/js-samples.git
Other samples can be tried by switching to any branch beginning with
git checkout sample-SAMPLE_NAME