When you turn the wheel, you are browsing on the current instrument type.
So if your instrument is a Bass Drum you are browsing all the Bass Drums.
If you hold Select and Press the wheel you can choose the Sound Engine (Sample, Analog, Physical).
If you press the wheel again (while holding Select) you can choose the instrument type (BD, SD, CH, OH...).
Release Select then choose you type (SD for instance), then your sound engine (Sample for instance).
You are now browsing what you want (all the sample Snares).