Bless your heart!, as we say in the south. Pull it. Pull it again. Pull it.....
You have to be very tenacious with this stuff. Is it in your lawn, shrub beds, ????
There are some high-priced herbicides marketed for nutgrass in lawns, but they also warn not to use them in the root zone of desirable plants. In other words, just plain old RoundUp is just as good and won't affect the roots of other plants.
I have read, and tend to believe, that nutgrass senses when you spray it and the nuts (tubers) will detach before the herbicide gets to them. I have several beds that I spray, pull, spray, pull. If you stay on them, you can get fairly good control.