I currently have a "clean" nightly configuration on a schedule and a "non-clean" manual configuration that both build code into the same folder. I'd like to have a single configuration for both where the user is prompted whether they want to clean the build or not when they kick it off, however I'd also still like to be able to analyse the build times of "clean" and "non-clean" builds separately. If I could filter the collected statistics based off a custom value (in my case whether the build was "clean" or not) then I would be able to merge my two separate configurations yet be able to still spot spikes in build times (as just merging them as they are would skew results)