I use these built-in categories to separate contribution types in a 401(k):
_401Contrib
_401EmployerContrib
When using the built-in Investment Performance report on the 401(k), the totals of both are combined into the Investments column. I could probably create a custom report to show them separated, but I'd like to request that these contribution types be separated into columns of their own in the built-in Investment Performance report.