Filter for archiving events before and after alarm

[Trembling6821]

I have some cameras set to always record, and a couple of filters to archive the events containing alarm frames and delete the rest. However, sometimes it happens that the alarm frames are at the very beginning or very end of the events, so that I do not have much context when reviewing later.

I would like to create a filter that archives the event containing the alarm frames, and also archives the event before and after that. I cannot figure out a way to do it, so wondering if somebody knows how.