gistfile1.js

var obj = {
  levelOne: {
    levelTwo: {
      property: 'Got me!'
    },
 
    levelOneArray: [1,2,3]
  }
}

function run(obj) {
  // Approach #1
  if (obj) {
    var levelOne = obj.levelOne;
    if (levelOne) {
      var levelTwo = levelOne.levelTwo;
      if (levelTwo) {
        var propertyValueOrUndefined = levelTwo.property;
        if (propertyValueOrUndefined)
          console.log(propertyValueOrUndefined);
      }
  
      var levelOneArray = levelOne.levelOneArray;
      if (levelOneArray && levelOneArray.length) {
        console.log(levelOneArray[0]);
      }
    }
  }
  
  // Approach #2
  var propertyValueOrUndefined = (((obj||{}).levelOne||{}).levelTwo||{}).property;
  console.log(propertyValueOrUndefined);
  
  var levelOneArrayElementOneOrUndefined = (((obj||{}).levelOne||{}).levelOneArray||[])[0];
  console.log(levelOneArrayElementOneOrUndefined);
  
}

// run some queries
run(obj);
run(null);
run(undefined);