I would think the R, G and B sliders of the "Black and White" tool do what you are looking for but I don't really know the technique you try to emulate. However there is a way to do what you want and that is to use Adjustments masks. So instead of applying the LUT and B&W to the Image Layer, add two adjustments masks using the + button. In one Adjustment layer apply the LUT and the other apply the B&T. You can reorder these masks layers to your liking and as you do that it changes the order in which they are processes. So you can make it so the LUT is applied first, and then the B&W after that.
Statistics: Posted by Martin Chalifoux — Yesterday 23:56:33