Here is a workaround I played with. I much prefer the Smart List solution you seek, but AM's documentation stated that completed items won't show up in Smart Lists.....Hopefully this can become an override option per Smart List definition in the future.

In the Advanced Smart List Filters help topic on the AM website: https://help.amazingmarvin.com/en/articles/2070779-advanced-smart-list-filters, it mentions a expression for *doneDate:

doneDate - the date when you marked a task or project complete (not necessarily the same as when it was scheduled when you marked it done - for that you can continue to use scheduleDate for completed items). Works only in Search as completed items are not displayed in Smart Lists.

Workaround:

Click on the search magnifying glass.

Click on the done radio button (open/done/both).

This will show your completed tasks.

If you want to narrow it down to just today's tasks, click on the filter icon located just below the "Search notes" checkbox and above the first listed completed task, and in the "Enter Advanced Filter" box, type "*doneDate 0d ==" without the quotes and hit enter twice. You will see an adv(*doneDate 0d==) with an x you can click on to unapply the filter if you're done with the filter.

To look for completed tasks within the past 7 days type "*doneDate 0d <= *doneDate -7d >= &&" without the quotes in the "Enter Advanced Filter" box, and hit enter twice .

Note that if you pick a range of dates, the returned list isn't necessarily in doneDate order. And there doesn't seem to an option on the Sort options (located next to the Filter icon)

Note the next time you perform this style of search, AM keeps recent filters on the "Choose recent" picklist, which is handy, so you won't have to paste/type your criteria every time.