Combined Contribution and Attribution Total

In the Contribution Report and Contribution Aggregate Report, you can add columns for Total Amount of Contributions and Total Amount of Attributed Contributions. These fields live under the Contribution Summaries section (see screenshot below). I don’t believe “Total Giving” as it is seen on the Contact Record exists as an out-of-the-box report field (to my knowledge), but you can add up the amounts from the two columns to get that number - either manually or exporting to a spreadsheet. 

However, if it is important for your organization to see the combined total in a report, you could achieve this by creating a Custom Calculated Field (if you have access to that feature). This would be visible in the Contribution Aggregate Report. See: How to: Add and use Custom Calculated Fields