The auto-suggest does not come from the BAA website. It is actually your web browser remembering what you have previously entered into those fields and then suggesting options based on this historic input.
It would be difficult to auto-populate object name and location from the filename as we would need to agree a standard filename layout that everyone would need to use, and otherwise gibberish would appear in those fields. There would also be a reasonable amount of bespoke development by BAA volunteers to write code to extract this information from the filename and populate the fields, assuming it is possible.
Sorry it is not better news.