Suppose you are processing a batch of Order elements, and you want to reject any Order element that has a validation error but process normally those that have no error or have just a validation warning. To do this, you must provide a grouping for any validation reporting at the Orders level by using the ValidateGroup function. Specify this function in the Validate expression tab of the element you want to be the group (the Orders element in this case). Any validation reports coming from subordinate elements will trigger this validation group and also cause a validation report for the group (which is associated with the triggering reports).
You can use the validation group as a filter in a loop using the IsValid function.