Using model with a query to one DB as a basis for a new query or CTE for another DB

Hello to all!
As I've read here:

with Metabase it's possible to use the results of one query(or model) within another query( as a subquery or CTE ).
But unfortunately I found out that it is not quite possible, when the saved query(or model) makes it's request to one DB and I want to use it then as a subquery or CTE for another request to another DB.
Is it really not possible or am I doing something wrong?

just a bump...

you can't do this if the queries are from different DB's... as the query is at the end compiled into SQL then it can't reference 2 different databases