How to persist multi value IBA using event listener (Create and Update)

You can listen for VersionControlServiceEvent.NEW_VERSION or VersionControlServiceEvent.NEW_ITERATION. See below article to update the attributes using Listener .

https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS99191&art_lang=en&posno=5&q=listener%20create&source=search

Also, You can set below verbosity  to true in wt.properties to check event keys  for create or update

wt.services.verbose

wt.services.verboseEvents

Hope it helps !!!

Thanks

Shreyas