Use audience targeting for search campaigns
1. Navigate to the search campaign or ad group within Google Ads where you'd like to apply audiences.
Audiences can live at the campaign or ad group level, but not both. If you already have audience targeting at a different level, you’ll need to remove it in order to apply it elsewhere.
2. Select Audiences from the side navigation menu, and click the + or pencil icon to add or edit audiences.
3. Choose Targeting to restrict the audiences who see your ad, or Observation to create defined audience segments without narrowing your reach.
Targeting will only show ads to people who match against one of your selected audience segments. Observation will allow ads to serve as normal, with performance data for the audiences you select. Both Targeting and Observation allow you to use bid adjustments for Search audiences.
4. Select Browse and expand Detailed demographics to define audiences based on segments such as marital status and education.
Expand each section to reveal multiple segments.
5. Select from the pre-existing categories of interests, habits, and search activity to define your Affinity and In-market audiences.
Select an audience category, or expand to select more granular audience subsets. Unlike Display audiences, you can’t create custom interest or in-market audiences.