EXISTS in the GUI?

We would love to use Metabase mostly because it's easy enough for someone without SQL knowledge to write queries. However there doesnt seem to a way to write an EXISTS filter without SQL.

Is this something that is possible and we haven't found it?
Is it a planned feature?
Is there some workaround we can use?

Is this a MS SQL only syntax?

No I mean like this

SELECT column_name(s)
FROM table_name
(SELECT column_name FROM table_name WHERE condition );

Available in most RDBMS

gotcha, there's no "exists" currently as a custom function