Not quite that, but macOS' new tabs-in-windows is close. I personally don't love keeping them all in tabs in a single window, but I can always select the Window > Merge All Windows option to gather all my disparate Finder windows together for this purpose.
(ETA: This wouldn't work in the save dialog though, I missed that detail)
(ETA: This wouldn't work in the save dialog though, I missed that detail)