In the current backup system, when you are on the screen to select which activities you want to back up or import, you can deselect or select an entire course section. Unfortunately, when you deselect a section, it disables the checkboxes for all of the activities within that section, meaning you cannot then go and select one or two from that section.
If you currently want to backup or import one activity, you have to uncheck all of the activities within that section that you don't want.
It would be nicer to be more like the 1.9 system where one box unchecks everything and allows you to select just the one activity you want to focus on.