Sometimes there is a harmonical conflict between the bass frequency and the kick frequency if the kick has too much harmonics on it (aka looks like a sausage).
This utility is used to map between the bass note that is playing (either the playing bassline or a “carrier” non-playing baseline) and the Frequency in the Drum Buss tool.
The tool will change the Drum Buss frequency according to the frequency that the bass is playing. This will make sure that the bass and the kick are playing the same note.
Note that the original kick would probably sound better if it is shortened and the “woof” is faded so that the actual kick and “woof” do approx 50ms and then start to fade