Detect Hidden ??Follow

I seen we have Detect Hidden, right now at lvl 16 I am 36/83. Has anyone used this skill and if so where and how do you use it.

If you been in the down below there are mobs there that I know for a fact use stealth (forgot the name but are skels). If you play a character other than scout they beat you up good before you can locate them. Scout can see tham and makes the group a little safer. I know this by the way because I have a brawler and she gets beat on down there where as my perdator can avoid tham.