The dimmer 2 can connect to 2 seperate switches (S1 & S2 - only one switch will directly control the connected load though). When parameter 28 is set to ‘1’ each switch will send the scene ID assigned to a particular action.
Using the CoRE Smart App you can take an incoming scene ID and do something.
For example, if I double click my hallway switch, it sends scene ID 14 to the hub, the hub then turns everything downstairs off. Same for my landing switch to turn everything off upstairs. (I only use S1 in these areas)
In my living room I use S1 to control the main light and S2 (Scene ID 26) to control a lamp in the corner. (One dimmer module). On the same module I can also double click S2 to lock a motion sensor, 3x click S2 to turn the whole house off except the living room and hold S2 to toggle external lights… Choices are endless and fully customisable!!
When buying new switches you should take this into account as an original 1 gang switch can become a 2 gang switch if you wish. You don’t have to use S2 though.
I strongly reccomend you swap out your toggle switches for momentary ones, scene ID’s work either way but you will get much better control of dimming etc with momentary switches.