Similar to the way labels and bid strategies are inherited in Search Ads 360, business data that you've applied to parent items is inherited by child items that don't explicitly specify their own business data.
For example, if you apply business data to a campaign, all ad groups and keywords in the campaign inherit the data. When you report on the data, you'll see metrics from all of the inherited items.
If an ad group and campaign are applied to different rows of business data from the same business data table, the ad group no longer inherits the campaign's business data, and its metrics will no longer be included in reports for the business data applied to the campaign. Instead, the ad group uses the business data directly applied to it, and the ad group’s metrics will be included in that row’s rollups.
Excluding Business Data is not supported
Because Business Data is inherited, it isn't possible to exclude Business Data for a child item if you've applied Business Data to the parent. You can specify different Business Data for the child, but you can't specify "no Business Data" for a child item if Business Data is applied to the parent.
In the example above, "Ad group 2" can inherit the "Sleepwell" hotel or be associated with a different hotel, but it is required to be associated with a hotel because a hotel has been applied to Campaign C.