We have some rather complex drowndowns, modals, and dialogues due to the amount of data some developers need to deal with. Big data requires big moves, you know what I'm saying?
Rather than going down a "dropdowns inside of dropdowns inside of modals" route, myself and another UX designer brainstormed around the posibility of chunking UI elements into we we are now calling "Panels", and then providing a way to easily navigate those "Panels" to facilitate contextual tasks at hand. This addition to our pattern library can work with in dropdown, as well as in modals or dialogue windows!
Displayed here is a visual I put together in Principle to go along with documentation as we propose this UX solution to the larger team at hand.