Analyzing User Behavior on Second App Visits: Seeking Solutions

hi! we are trying to understand what our users do upon their second visit to our app? does anyone know what the best way to do this is? we aren't able to rely on the session events because it doesn't keep track of which instance of session it is so we aren't able to determine the 2nd visit. Retention reports don't seem to help out either because they can't tell us what users do once they return to the app for a second time, only that they have returned.