Several VPN area in one router

I have several PCs and they are connected to my router.

I want to separate them and have access to them via VPN based on the following requirements:

1- PC1 and PC2 are on VPN1, so when I connect from outside to VPN1 that contains these PCs, I can see both PCs and can log in to any of them and both PCs can see each other (A virtual LAN).
2- PC3 and PC4 are on the VPN2, so when I connect from outside to this VPN server, I can see PC3 and PC4 but not PC1 and PC2
3- The VPN servers can have their public IP or separate ports.
4- I need at least 4 areas (so VPN1, VPN2, VPN3, VPN4)

What type of hardware do I need?

Is a router which is based on openWRT can support this type of requirement?