- add a chain device
- add a tool in the first slot
- add the thing you want to sidechain after. make its sidechain input the tool device.
now save the preset. call it something like '<device name> SC'
you can now open the preset whenever you want to sidechain that device.
you can drag the tool wherever you want it to sidechain from.
as long as you dont put it somewhere where bitwig doesnt allow sidechain routing, it'll just transparently move the sidechain source wherever you want it.
now you dont have to go through the lists to set up sidechain.