OPNsense will do what you want, although it’s probably overkill in this case. Also keep in mind that any switching it does will be purely software, so it might struggle to push heavy traffic through, especially if you add rules and vlans and such. Openwrt is more lightweight and should also work, or you could just install a general Linux OS like Ubuntu or debian and use iptables to route stuff. The better option though is to just get a proper switch, since those have hardware switching.