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Dropbox integration: save submissions in the same folderAsked by DPCREATE on July 02, 2015 at 10:45 AM
If the users resumes the form later they will be able to add to the additional files, however not that in the submissions data the previous uploaded file will be replaced with a link to the newly uploaded file since any data that changes is updated with the new value.
I hope this clarifies your question.
Regarding adding to individual folders, do you mean appending new submissions to an existing folder instead or creating a new one,
You can use a user defined options for a folder you want.
Kindly refer to this guide for additional information