Why? I just recently introduced Tradfri to my home and I want to write some generic code that sends telegram messages for low battery states or low RF signal of a device in my setup. And I do not want to create dedicated channels for each and every device, when I possibly can make this generic by listening to e.g. zigbee2mqtt/+/battery. But then I’d need to find out what deviceName the + matched.
In the Event Channel set the “Separator Character”. As the description says
The trigger channel payload usually only contains the received MQTT topic value. If you define a separator character, for example ‘#’, the topic and received value will be in the trigger channel payload. For example: my_topic#my_received_value.