Is if feasible to modify the ticket assigned user filter to allow multiple selections?

I would like to make it so the ticket list “Assigned User” filter will allow multiple users to be selected in the search.

Has anyone done this before? Is there a mechanism provided to make this change?

I do not think there is one for tickets, but there is that possibility for projects, so Dolibarr does have something similar.

Looking more into it, not only does Dolibarr use exactly the same database table and public function to handle getting the assigned users, but I even think it is possible to to what you ask for.

Code function dolibarr/htdocs/projet/class/task.class.php at develop · Dolibarr/dolibarr · GitHub

Home, Tickets, List, click on one of your tickets, select the 2. tab: “Contacts/addresses”

I think you can add multiple internal users and multiple external contacts.