When to use delete current child object
Suppose you have an array of elements then you want to delete current index base object then you can use delete current child object task on the basis of business rule or what your business meet expectation from you.
In this task you have to pass LV Object array path in to the JSON Path.
When this task is applied, it deletes currently selected child object. When user performs the action to delete currently selected object, this task executes to capture the value of currently selected object and then searches the object in the array type JSON object. If the object is found in the JSON array, the Delete Current Child Object task deletes currently selected child object in the array.
Please refer this document for better clarity -