GameObject Tags

I have a big sphere and i want to when all objects in this sphere with tag “Path” have PathState == 1 then level has been completed.

You can iterate through all of the objects and check their state

bool isCompleted(){
	foreach(GameObject g in GameObject.FindGameObjectsWithTag("Path")){
		if(g.GetComponent<YourScriptsName>().PathState != 1){
			return false;
		}		
	}
        return true;
}

This little bit of code returns true if all objects PathState == 1 and false if one or more objects PathState != 1