Find dates until next event from filtered start and end events

[cplesner]

Hi

I would like some input on how to get the best performing DAX calculation for calculating time between selected events. Let say i have below source table with millions of people and events.

In my PowerBI matrix I would like to be able to select a Start Event and an End Event and then have it show the following

Or if i select another filter, then this

Any help is appreciated

[littlemojopuppy]

Can you paste some data to work with?  Difficult to work with pictures