What division is doing this?

Hello, WSO folks! Lately I've been reading a number of articles regarding complex products / derivatives designed by (in examples below) Deutsche Bank, Blackstone.

Deutsche Bank AG (DBK) designed a derivative for Banca Monte dei Paschi di Siena SpA at the height of the financial crisis that obscured losses at the world’s oldest lender before it sought a taxpayer bailout.

Blackstone Group LP (BX), the world’s largest private-equity firm, has devised a way to profit from regulation: It’s helping banks meet tougher capital rules without the pain of selling assets or raising equity.

There are many examples in past months, I just want to give you feeling of what I am talking about.

I was wondering, what kind of department is working on making such complex derivatives and unique structured banking products? Is it Structuring dept within S&T? Or is it special IBD group? Or is there some dedicated transaction advisory arm?