It is done by collaboration within your own squad that you are member of. And each squad member can help to make this raise quicker if you help each other. Aka: Squad points are made when healing a squad mate, reviving a squad mate, being a spawn point, capping a designated flag, etc.
If you lone wolf, your squad will take more time unlocking them. Same goes if your squad leader does not give orders. Only the squad part of the points will go toward raising your 'soldier perks' level. So let's say you get a squad savior, you get 25 for the savior and 25 for the squad part, only 25 points will go in your perk progress.
You lose your progress toward your next level and a level when your squad is wiped. E.g. meaning that none of your entire squad is alive. So that is what you really need to avoid at all times, to keep growing your perks level and to keep them all at top! If you are alone, you will wipe everytime you die, so that is obviously not the ideal way to play. ;o)
So team up and play as a team ! Everybody in the team makes more XP also at the same time, so truly a win-win-win for all !
