How can i map this????

How can i map this???

Hey all, im wondering if its possible to hit a button, lets say the c button, and have it invert the crossfader using traktor pro 2?

You will have to make that certain button a modifier and add that modifier in the inverted crossfader mapping. I recommend to either map it so you have to press that button to invert the xfader (and press again to bring it back to normal mode) or only invert it when that modifier button is being pressed, like a shift button on most controllers/keyboards.
First one would be the same modifier twice in direct mode, one with a condition that it has to be 0 and raise it to 1, the other one with a condition that it has to be 1 and decrease it to 0. The other option would be a normal hold-modifier.
Feel free to ask if you need the specific commands.

Thanks for the reply! Ill try to do it myself because i need to learn how to use modifiers, but if i cant ill be asking you haha