Multi-Table Search Demo
MultiTableSearch searches several Dataverse tables at once and lists what matches together, and MultiTableSearchBox suggests the first matches as you type, from anywhere on the site. Every row is read with the visitor's permissions.
Search the demo's customers
A search box as a site's header would have it, above the search page it sends you to: here, this page. The demo's accounts, contacts and opportunities, ten at a time. See the Multi-Table Search documentation to add it to your pages, and On a Single Record for the search on one customer's page.