Only available in Google Ad Manager 360
Audience Solutions is a Google Ad Manager 360 feature which might not be enabled for your network.
You can generate reports to see the targeted, billable segments that caused line items to deliver.
To view audience segment data, follow the steps to create a report from a template. Then, choose the Billable audience segments report as your template type.
Alternatively, you can create a new report and choose Audience segment (billable) as a dimension.
Learn more about why you're being billed for a particular segment.