Draft, Research, etc. (the Binder) are coded in the .scrivx XML index file, which you never see on a Mac unless you go to extra trouble to see it. (Don’t.) All you should see on the Mac is the .scriv.
There are no sync settings on the Mac other than placing your project in a Dropbox folder.
iOS Scrivener’s default sync location setting is ~/Dropbox/Apps/Scrivener, but it can be any Dropbox folder so long as the location on your Mac is the same as the location setting in iOS Scrivener.