Hi,
Thank you for confirming. All the criteria associated to campaigns and ad groups can be retrieved with the Google Ads API by querying the resources campaign_criterion and ad_group_criterion.
Both of these resources have many fields that you can filter on including "type" (CriterionType) that should be especially helpful in your case. Note: the targeting dimension AUDIENCE includes multiple types of criterion (user list, user interest, custom affinity, and custom in market).