I have Fibaro Dimmer and Fibaro 2x1.5KW Relay with three loads connected individually and using two separate 2-way bistable switches per each Fibaro device. I want to use the association to link the switch of Key No. 2 in Dimmer to control Key No. 2 on 2x1.5KW Relay. I found I only work to control the root switch and Key No. 1 of this 2x 1.5W Relay but fail to control its Key No. 2 of relay in any way. Is it a problem to make the association to Key No. 2 of Fibaro 2 x 1.5 Relay from another Dimmer? If not, any workaround?
If you check the associations for your dimmer, you’ll probably find that it is not associated with switch #1 but with the root device of the Fibaro double switch. The way it is supposed to work (I haven’t tried this) is that you associate with the root device on group 1 to control switch 1, and associate on group 2 to control the second switch.
You could try to associate key #2 of your dimmer to the root device using group 2, but I’m not sure if the dimmer transmits on group 2 when you use the 2nd switch. It will work if you use switch #2 of another Fibaro double switch.
Thanks. In root device of dimmer, I can sucessfully set the association to the root of another double switch and control its ON and OFF. When I try to add the second switch or only take the second switch using Group 2 of dimmer, it have not accepted at all. That’s the reason why I think it seems not support for the child’s second switch association from Primary’s Dimmer to Child’s Double Switch. I don’t know why and how to fix it? Actually, I use this method to fix my 2-way lighting from my original light wall switch 
I tried several cases that the association for Group 2 of Fibaro 2x 1.5W double loads for switch ON/OFF from another Fibaro Dimmer, 1x3KW even 2 x 1,5W is NOT possible. I can only make the association with its root device → Group 1 only. I can set the association on Group 2 (Device option → Group settings) but can’t view it in in the root device. It should be a bug. If not, anyone can help?
I am trying desperately to associate my minimote with different buttons of the Fibaro 2x1 relay switch. I think it is the same problem. It is a real nuisance
Confirmed with Fibaco support, it is a problem. We can’t do this kind of association to Key No 2 at this moment and they said will have update in the future.
Is there any update or solution since April?