Hi Kevin,
We worked around this with a custom form. Create a User custom form (or leverage your existing one) and create a calculated custom field from the following logic (borrowed from a post in the old community days):
CONCAT(IF(!ISBLANK(Manager),Manager),IF(!ISBLANK(Manager.Manager), ", "+ Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager), ", "+ Manager.Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager.Manager), ", "+ Manager.Manager.Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager.Manager.Manager), ", "+ Manager.Manager.Manager.Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager.Manager.Manager.Manager), ", "+ Manager.Manager.Manager.Manager.Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager.Manager.Manager.Manager.Manager), ", "+ Manager.Manager.Manager.Manager.Manager.Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager), ", "+ Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager), ", "+ Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager),IF(!ISBLANK(Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager), ", "+ Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager.Manager))
Make sure you attach this custom form to your users.
Now, in your report, use a filter that takes this Assignment Users >> [custom field] with the contains operator and the value is $$USER.name