I cannot find a rendered file in this unit.

A rendered file will be created at root (of USB storage device)/PIONEER DJ SAMPLER/Rendered Audio/[Project Name]/.

You cannot refer to that directory from this unit because it is not "Samples" folder, so please connect to your computer and move or copy the rendered audio.

If you want to use a rendered audio file as a sample, please use the RESAMPLE function in HOME > TRACK MENU > SAMPLING/EDIT.