Hi,
My idea is the result column from first view is used to insert into a temp table where it is used for joining to the 2nd view. The 2nd view will only returns records when there is a valid join by the temp table record upon a SELECT on the 2nd view. Hence you always need to truncate the temp table first before inserting new selection.
On the other hand, will the INSERT operation slow down the performance, you test and feedback here later. Maybe what you doing presently by a 2 DB calls maybe better efficient too 
Regards.
YS