I'm thinking something along the lines of small, elite units trained for stealthy, high risk operations and/or forward reconnaissance.
I understand lots of societies had a warrior elite, but someone like a Knight or Samurai doesn't really seem too well suited to what we'd think of as a commando raid.
In one word, no. The idea of "special operations" or "commandos" is a thoroughly modern one and not something that can be applied to medieval warfare in any meaningful way. There have been a number of threads on this subject in the past (with varying levels of quality), but I believe /u/thegreenreaper7 summed it up best in this post.