You can see your buying activity per publisher partner by adding 'Publisher' as a dimension in your report.
Open Market & Deal ID Activity:
To see your buying broken out by Deal ID's vs. Open Market, you can run a report setting 'Spend Source' as a dimension.
Deal ID Reporting:
To report on your Deals, you will need to add the dimension 'Supply Tag', and then add a filter for Spend Source to be "Deal Bought".
Dimension and Filters for a Deal ID report:
Deal ID report results:
Open Market Reporting:
To view inventory sold to your Open Market, run a report with 'Supply Tag' as the dimension, and as a filter for Spend Source filtering for 'Open Market Bought'.
Dimensions and Filter: