UI File Upload

We have created a document upload UI similiar like Image right as user wanted it like that.It has folder>subfolders or option to add one> document are uploaded.

I have used for each to show hierarchy of folder then subfolders and file upload.issue is When i want to upload document to a particular subfolder it is populated in others subfolder file upload as value field is same for all.So I want to upload different douments in different subfolders(as we do in our PC) and should be able to save them.I have tried a!map but it does not support append.