In your Mediamath DMP, you will be able to find AudienceData as branded data under Adform.
Under the Targeting tab, select Audience and find Adform. Then select Branded Data and choose AudienceProject.
Here you will find all the AudienceData segments available in the MediaMath DMP.
If you have any questions in regards to this, or in relation to AudienceData in general, please feel free to reach out to our client services team at firstname.lastname@example.org