Hmm.
There are definitely knobs with buttons underneath - I’m thinking of Playstation 4 and other gaming controllers where the main joysticks (ok, not perhaps technically a knob!) can be clicked.
But pressure sensitive buttons underneath are not something I’m aware of. I’m sure it could be hacked together with an FSR (example: http://www.interlinkelectronics.com/FSR402.php) if you have the desire and skills to get your hands dirty.