Nikon D500 has a
21.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor and features Expeed 5 processor. On the other hand, Pentax KF has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features PRIME MII processor.
Another similarity between these two cameras is that both Pentax KF and Nikon D500 sensors lack anti-alias (Low-Pass) filters. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the D500 and KF sensor size comparison.
Nikon D500 and Pentax KF have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.