code: function(fieldArray, container) {
         if (YAHOO.lang.isUndefined(container))
  			container = this;
  	
        for(var i = 0 ; i < fieldArray.length ; i++) {
      	  var inputParams = fieldArray[i];
      	  inputParams.container = container;
  
      	  // Checking for group sub elements
      	  if(inputParams.fields && typeof inputParams.fields == 'object') {
      		  this.setBackReferenceOnFieldOptionsRecursively(inputParams.fields);
      	  }
  
      	  // Checking for list sub elements
      	  if(inputParams.elementType) {
      		  inputParams.elementType.container = container;
  
      		  // Checking for group elements within list elements
      		  if(inputParams.elementType.fields && typeof inputParams.elementType.fields == 'object') {
      			  this.setBackReferenceOnFieldOptionsRecursively(inputParams.elementType.fields);
      		  }
      	  }
        }
     }
docs: When creating wirable input fields, the field configuration must have a reference to the current container (this is used for positionning).
  For complex fields (like object or list), the reference is set recursively AFTER the field creation.
  @method setBackReferenceOnFieldOptionsRecursively