@Snailkhan:
It is not possible in pfSense to tie IDS/IPS rules or policies to the pf firewall engine. Thus it is impossible to tie IDS/IPS rules to IP source or destination pairs as evaluated by the firewall engine. That's just not how pfSense is designed. If you need this level of granularity, then pfSense is not the product for you. The best you could do is write your own custom IDS/IPS rules where you customize the Source/Destination fields of each IDS/IPS rule. I seriously doubt you want to get into that level of maintainence.
Snort is an add-on volunteer-maintained package for pfSense. It is not baked into the operating system nor into the design of the firewall. Therefore its capabilities will be nowhere near as flexible as say a customized Cisco hardware/software solution might be.
Later Edit: but compare the price you pay for pfSense and its Snort package to what the Cisco solution costs you 😁. Many times compromises are necessary when taking advantage of the "free" option.