Windows 10 Bridge Network Connections but Choose Which Internet

Hi,

I have a PC that I want to use as a media server. This PC is connected directly to it's own internet (Router A) and via Ethernet to another router (Router B) that also has it's own internet.

I want devices connected to Router B to have access via the network to shared files on my PC, but I want my PC to use internet from Router A only.

Is there a way I can Bridge the network connections and select which connection I want to use for internet?

Alternatively, is there another way (other than Windows Bridge connection function) to connect my PC to both routers and only use one Router for internet?