Hi Utku, unfortunately I dont believe this is possible because it would require a join and sub-query to run first to pull back all of the groups the logged in user is a member of, and then go grab all users from all of the groups the logged in user is a member of, then take that list and pull all tickets that are assigned to that list of users. That cannot be done via a stored query. Something like this would need to be done in a report, or you could open an enhancement for this type of thing by posting an "idea" here on the community.
Thanks,
Jon I.