Hey Fredo,
Taking over for Scott here, I am Dorothy, and I'd be happy to help!
Thank you for responding Vlad, I believe you are right! If you'd like to cover the following criteria: Y days that followed their first Z event, you can use our Funnels report. Inline Attachment: image.png You can update the Y value by updating the conversion window from "Within 7 days" to "Within Y days".
Here is a sample funnels report using our demo dataset as reference: https://mixpanel.com/s/3H8GvC
In this case, I have set the Y value as "3 days".
You can then create the cohort by clicking the relevant segment on the Funnel, clicking "View Users" and click "Create Cohort". Please note that Cohorts created from Funnels can't be edited, but this should address your request.
Here is our Funnels documentation for reference: https://docs.mixpanel.com/docs/reports/funnels/funnels-quickstart
Would this work for you? Please let me know if you have any further questions! Warm regards,Dorothy
Support Engineer @ Mixpanel | Singapore (GMT +8)