If you are a user of Cost Transparency versions prior to 12.2, you can automatically retrieve actuals for Interactive Benchmarking. See Video: Configure Interactive Benchmarking: Auto Upload Actuals from Cost Transparency (8 min.)

However, if you are a user of Cost Transparency version 12.2 and later, you can manually input actuals for Interactive Benchmarking. See Interactive Benchmarking - Manual Configuration Guide (PDF) 

The ability to automatically retrieve actuals for users of 12.2+ is planned for future release in Q3, 2017.