In the settings for the PIA client check "Don*t pull routes" to avoid that you get pushed the default route from the server.
Then set up a policy routing rule like that:
Add an alias "NoPIA" first and add the networks 10.10.1.x, 10.10.2.x and your pfSense LAN address to it.
Add a firewall pass rule to your LAN (92.168.1.x):
source: LAN net (the 192.168.1.x network)
destination: check "invert match" and enter the alias "NoPIA"
Open the advanced options, go to gateway and select the PIA gateway.
You have to assign an interface to the PIA-VPN first.