Business data is "one to many"

A single row from a business data table can be applied to many Search Ads 360 items, but each item—such as an engine account or campaign—can only have one row from a given table applied.

For example, a hotel can be applied to many campaigns, but each campaign can only be applied to one hotel.

You can apply data from different business data tables to a single item. For example, if you define a business data table for hotels and a separate Business Data table for restaurants, you can apply a Hotel and a Restaurant to a single campaign.