"With Google Custom Search, add a search box to your homepage to help people find what they need on your website." (emphasis mine)
Their video also seems to indicate the same thing: https://youtu.be/Qd9z48Bo8ZA
They say you can search "one website or even a specific topic across multiple websites". This is specifying multiple domains, not a full-index search.
"With Google Custom Search, add a search box to your homepage to help people find what they need on your website." (emphasis mine)
Their video also seems to indicate the same thing: https://youtu.be/Qd9z48Bo8ZA
They say you can search "one website or even a specific topic across multiple websites". This is specifying multiple domains, not a full-index search.