Is this making a buttonhole in the ribbing? If so, yes, you would sl1, k1, p1, k1, pass the purl over the knit and off the needle. Purl the next stitch and pass the knit over this purl stitch (2sts cast off). Continue with k1, p1 to the end. Leave the initial 2sts (the slip st and the k1) on the needle.
I like the video for binding off in pattern. GG, thanks!