Filter all traffic from a static LAN IP except some specific ports through a VPN

Hi!

I have a Ubuntu server where I want to filter all the traffic except some specific ports through a VPN connection. The traffic from the specific ports should go through my WAN connection. I had hoped I could solve this on the Pfsense router with firewall and NAT rules or something similar.

how I can solve this ?? The Ubuntu server has a static IP in my LAN