If you want a solution for 3rd party payware real sidechaining see:
Sets up and manages 2 send tracks and the send devices routing to them, to mimic the effect of sidechaining a kick to a compressor. By feeding the left channel of the compressor the source kick and the right channel the signal that you want compressed you can essentally drive the compressor with the kick. Splitting this up into 2 tracks for left and right channels and panning the outputs, you only hear the compressed output of the non-source-kick signal. The reason this is not real sidechaining is because the compressors detector is still reacting to the non-kick signal, but the sound can get fairly close , particulartly on non bass sounds.
As you are using parallel send tracks, the tool also syncs the devices in both sends and provides a gui for managing this.
1) "Global:Tools:Set Up Fake Sidechain"
Sets up the sidechain tracks and the sends.
2) "Global:Tools:Sync Fake Sidechain Sends"
Opens the GUI to manage the devices:
Add your compressors to the “SC Left” send track and click the device you want to adjust via its button in the gui. The button turns green to show the devices are linked. If there is a plugin gui it will open. You can now adjust the parameters and both instances of the compressor are updated simultaneously.
1)" Instrument Box:Set Up As Fake Sidechain Source and Kick Track"
Load a kick sample or kick plugin to an instrument slot, then use this menu entry. A sidechain source is added with a kick on every beat. the instrument is duplicated and a Kick track is added also along with all relevant routings
2) "Main Menu:Tools:Ledger`s Scripts:Sync Fake Sidechain Sends"
Opens the GUI to manage the devices (same as the above shortcut)
The routing window is to manage the send devices routing to the 2 send tracks. This is accessed via the routing button on the Device Manager GUI. Below you can see that there is a SC Source track routed as the single source. This track is silent when routed like this and usually will contain a 4X4 kick. The next track is the Kick track which has no routing so is uneffected. All other tracks from Bass downwards are routed to the SC Sends and are effected by the compression. Change the states as you wish. You may want to just have the Effected routing on group tracks for instance.