Subform data records relate back to their parent record using PARENT_RECORD_ID, PARENT_PAGE_ID, and PARENT_ELEMENT_ID. These values are found in the record meta data and help you maintain the relationship between your data, no matter how complex the structure.
***When using subforms it is recommended that you DO NOT give out collect rights to the forms being used as "subforms".***
When reviewing data in List view that has subform records, you will see a Subform(#) for the subform element.
If you click on the Subform(#)it will take you to the record(s) that were collected inside the parent form.
Another way to view subform data is to go directly into the subform records that were collected from Data Views just like you would a "parent" form. You must have been given rights to View data for that specific form in order to go directly to it.