Finally, I found the “other” notation. So, it’s possible to configure knx bridge and knx things in separate files:
Bridge knx:ip:myBridge "My Bridge" @ "knx" [
type="TUNNEL",
ipAddress="192.168.178.55"
]
Thing knx:device:myDevice (knx:ip:myBridge) "My Device" @ "knx" [
address="1.1.1",
fetch=false,
pingInterval=600,
readInterval=0
] {
Type switch : ...
}
So, the bridge is set explicitly through the round brackets. I did a short test and this notation seems to work.
See MQTT 2.4 documentation for reference. Thanks to @crxporter for giving the hint