Indoor and Outdoor Mileage

As far as I can tell you cannot segment accumulated miles between those earn riding outdoors and those earned riding on a trainer.  This would be a great feature to include in a future update.

Zwift only records miles done within Zwift, I don’t think it will ever track IRL rides/miles. You would need to use Strava, TrainingPeaks or other 3rd party site for this.