How I assign choke groups for multi mic hi hats in Kontakt:
HI HAT DIRECT MIC
Hi Hat Full Open, Direct Mic, assigned to voice group 1, 1 voice polyphony
Hi Hat Fully Closed, Direct Mic, assigned to voice group 1, 1 voice polyphony
HI HAT OVERHEAD STEREO MIC
Hi Hat Full Open, OHS Mic, assigned to voice group 2, 1 voice polyphony
Hi Hat Fully Closed, OHS Mic, assigned to voice group 2, 1 voice polyphony
etc...