If I understand what you are asking it is that you have loaded a bunch of audio samples into a drum program and you would like to adjust those each individually.
If this is the case, you can adjust the BPM of each sample in the "Sample Edit" section from the "Menu" screen.
Rather than search from the samples list I find it easiest to make sure you are on the Drum Program track you want, and then go to the "Step Edit" pad mode (the button on the left, not from the "Menu" screen.
Then from the "Menu" screen click on the "Sample Edit" mode. Now whenever you click on the drum pad it will automatically show the appropriate linked sample on the screen and you can adjust from there.