Obviously there is no option to simply copy&paste (sub)folders in Rig Manager. I don't understand why such a limitation exists in RM, considering copy/paste of profile(s) works perfectly.
I found a workaround, though. Going to RM Local Library folder with Explorer/Finder and rearranging folder structure directly seems to do a trick. Next time you open RM, changes are instantly reflected in folder structure.
Any other suggestions? Is this the way to do it?
Yes, this is the only way.