LibreNMS alerts entities association


I’m a user who are moving from Observium to LibreNMS. So migrated devices, now i’m starting to add alerts.
My question is: how to select specified the entities/devices on which the rules will work ?

As i see the only way to select the entity is via: “Match devices, groups or location”.
But this seems not very flexible. Maybe it’s possible to select the devices in the same section where the Alerts tests are defined ? For example the alternative way could be to add devices.hostname.equal == CORE01.
Or this way is not recommended ? Thank you.

P.S i see that here in LibreNMS port groups are not possible to define, yes ?