Brownie to help you out, GTM 3 , has a limited amount of information they need to know to be able to be called a "GTM" they have little to no field experience, can not RON, and usually only stay somewhere for a few hours and then get relieved, they know the basics of finding people, and how to treat certain stress induced problems. and know the basics of compass.
GTM 2, have the ability to RON, and need to be masters at navigation, and map work, but still have the ability to find the person and complete the objective, they may stay in the field for about a day or so, and maybe overnight.
GTM 1, are the best GTM', and need to have everything mastered, they have the ability to RON for a few days if needed, and can still get the job down to the best of heir ability. they know how to coordinate with aircrew's, and work with dog teams, and they know how to organize, plan, and produce a search line, and hasty search operations. the next step up from them is GTL.