How to create superimposed actor?

Hi guys, I ask your help. I want to make country selection like Paradox Interactive games(or something similar).
That is to say that on the globe there were several countries that can be selected. With what would you have done?(I mean, multiple meshes and assembly in one, overlay 2D and …).

Video with my globe - - YouTube
Video UE4 - Europa Universalis IV Gameplay Review - YouTube

Many thanks for your help.
p.s. I would be very grateful if you would have told me what books have on the development of economic strategies (that I do not terrorized you with stupid questions)