How to create a multiple combobox/dropdown with multiple dropdown inside a dropdown

I’ve research a lot of stuff ranging from youtube, forums and learn some components like, vertical layout group, layout element, content size fitter, scroll rect etc. but none of those tutorials or forums say and tell how to make multiple of them.

the Image in here is what I plan to make… but UI development is not really my forte…

only problem I am having is how do I move those Objects, Systems, Particles. etc. below when I open the Camera Tab. ?