How are the field names in the output tab in the data cleanse Transform are derived?

Hi All

       Please help me in understanding the few facts related to the "Data Cleanse Transforms" . Below is the relevant image i am referring to :

I am confused regarding the Fields which are getting displayed under the "FIELD_NAME" in the OUTPUT Tab(which is in Data cleanse transform),Where from these fields arrived. Did they arrive after running the job? Because these fields needs to be mapped in the output schema and they ain't available in the input ,moreover they have been named in accordance to the order of  -> PARENT COMPONENT , FIELD_NAME, FIELD _CLASS  with underscore attached.

I need to use the above concept in my example too.But when i tried using it, the fields under the output tab were empty