Its pretty simple you can open 3 different nautilus windows or open 3 tabs in nautilus. Not really very different then dolphin's function but I found myself never using that function in dolphin anyway. I have a good example for a many window workflow that I do sometimes which is when I tag my music. Usually I have a web browser on one workspace or the music tagger split in half with the web browser and then I have separate work spaces with nautilus open in 2 windows with some tabs. I do all that alongside a game playing in the background casually and maybe a picture-in-picture window alongside that also open watching a video. I only have one monitor.

Please help me I've been balancing the donkey on this seesaw for 30 years