You can configure this Policy or Computer to inherit its Interface Isolation enabled/disabled state from its parent Policy or you can lock the setting locally.
When Interface Isolation is enabled, the firewall will try to match the regular expression patterns to interface names on the local computer.
Only interfaces matching the highest priority pattern will be permitted to transmit traffic. Other interfaces (which match any of the remaining patterns on the list) will be "restricted". Restricted Interfaces will block all traffic unless an Allow Firewall Rule is used to allow specific traffic to pass through.
Selecting Limit to one active interface will restrict traffic to only a single interface (even if more than one interface matches the highest priority pattern).