Require [Role A + Role B] to receive a ping to [Role A]

Let's use a general gaming server example to illustrate the functionality — you can apply several gaming roles to yourself in the server to show people which games you play, but these roles cannot cause notifications by themselves. However, you can also apply another role to yourself, e.g. "Looking for Game" in this instance, which, when pinged in combination with one of your game roles, will send a notification to you.

An alternative example would be support staff in a development server. You can selectively apply the "Available" role to yourself, so that only support members that are presently capable of helping with an issue receive the notification.