You cannot reference correlated attributes that exceed the scope of a SQL-derived table from a SQL-derived-table expression.
select * from publishers where pub_id in (select pub_id from (select pub_id from titles where pub_id = publishers.pub_id) dt_publishers)
Here, the column publishers.pub_id is referenced in the SQL-derived-table expression, but it is outside the scope of the SQL-derived table dt_publishers.