Connecting 2 different networks (routing / Gateway)

I have a basic question about connecting two networks, and the routing / dns settings required:

• Network A (company, 2008 R2 Environment) is a Domain-Network, containing it's own dhcp, dcs, Internet-Gateway, etc.
• Network B (home, 2012 Environment) is a Domain-Network (different domain), containing it's own dhcp, dcs Internet-Gateway, etc.

Both Networks use a different (local) IP-Range, which is quite helpfull I assume.

Currently i'm in progress of building a new home, where the company is visible "Bee-Line", which would theoretically allow to connect both sites through some directional-wifi connection. (Devices for this purpose support up to 50km, but it's only as little as 2km)

So, I'm quite familiar with dns-setups, but never done a real "routing". What would be required to "teach" every network how to connect to devices on the other network - i.e. use a second gateway/router to connect to a certain domain?)

ps.: I'm seeking for a solution that - if possible - can be auto-delivered in the respective network through GPO / DNS or DHCP-Settings. "Local Configurations" of clients should be avoided.

pps.: I want to keep the networks isolated (own DC / DHCP etc.), only routing requests between hosts on either network

Example:

best, dognose