ios - Sprite Kit Select SKNode below another SKNode -

i'm creating ios app sprite kit & i'm trying select (ontouchbegan) sknode lies below sknode. structure : firstlayer(sknode) - secondlayer(sknode) & 3rd layer (sknode). i'm trying select secondlayer , move around ontouchmove. current problem touch recognises 3rdlayer. can me ?

to elaborate on scott's comment, zposition property of sknode layer lies on, higher layer numbers being "closer" front of screen. therefore if want have nodeb on top of nodea, nodea have zposition higher number of a, such as:

nodea.zposition = 1 nodeb.zposition = 2 

if set zposition of node when create it, can set conditional check on zposition of touched node in 'touchesbegan' method. following above example, if touch nodea , notnodeb, check zposition of node being touched equal 1:

-(void)touchesbegan:(nsset *)touches withevent:(uievent *)event{     uitouch *touch = [[event alltouches] anyobject];     cgpoint location = [touch locationinnode:self];     sknode *node = [self nodeatpoint:location];      if(node.zposition == 1){         //do stuff nodea here     } } 

i think scott getting at, hope helps.