@mark > As @roBRoy says, if you have the DJ plus-pack installed (allowing you to use rekordbox with a controller and DJ from the software), in PERFORMANCE mode, you can click the SAMPLER button at the top of the screen to open the sampler pane.
If you would like additional samples, there is also a free plus-pack available for download within rekordbox:
2. [File]>[Import]>[Download Sampler Plus Pack]
3. Save a file: “SAMPLE_PACK.app” into your Computer.
4. [File]>[Import]>[Import Sampler Plus Pack]
5. Select “SAMPLE_PACK.app”
Then, the sampler plus pack can be automatically imported, analyzed and shown in the Sampler category of the tree view.