If you can have it send a notification as a routine then you could use that notification as a trigger for MD.Or a zigbee - connected button. An IKEA button can start some routines. Great if they can trig macros.
It will depend on the features of the actual Bluetooth button, but for example triggers such as Home Button Long Press, Media Button Pressed, Volume Button Pressed, Volume Button Long Pressed.Thanks for the hint - but I have a hard time seeing how it can trigger a MacroDroid macro ...