wire up all inputs to the filter.
put the rack on two tracks (in your case the signal track and the side chain track).
// Specific to side chain stuff
Most likely the signal you are using to sidechain you'll also want to have playing as normal, so in this case create an extra set of outputs in the rack.
route the side chain inputs to both the compressor *and* the new outputs. When you place this rack in the side chain track, you'll need to also set the rack outputs to use these new 'pass-thru' outputs.