How to filter ticket using OR condition

Hi Guys.

First message in that forum, so I'll start with a big thank to the team for that great tool.

I'm succesfully deploying projeqtor in my enterprise (starting for a use of ticket). In the filter option, I don't find any way to put a OR condition. Actually what I would like to do is:

Filter the tickets for which:
- responsible amongst user1 and user 2,
OR
- responsible is empty

Did I miss something or would it be a enhancement to plan?

Best regards.

Arnauld