I will leave this as great idea for PR for later for someone.
- Add to web radar option to display two map levels as overlay at once render window. Render all players together on two overlays backgrounds on top of each other.
- Add setting option to render players on lower level map with additional marker (arrow or something)
- Add setting to disable such behavior and keep separate layers on separate render windows (as it is currently)
I will leave this as great idea for PR for later for someone.