I am not able to filter the tasks assigned to a specific person.
For example, what is the syntax to filter tasks assigned to a specific user sharing a project (e.g. john Doe)?
Unfortunately, that's not possible right now, but we'll consider adding such option in the future and you're welcome to vote for it in our Votebox: https://todoist.com/Vote/show/7785/
The Votebox is closed. Is this feature coming anytime soon?
We're not currently working to bring this functionality right now but it is possible that we'll add it in the future.