Collapsible Tree Structure View in SharePoint?

Is there any way to create a collapsible tree structure in SharePoint that would not only allow me to create an easily browsable structure (with + and – buttons to collapse and uncollapse each section) but would also allow me to upload a file (e.g. pdf or xls) under the last level of the structure so that a person viewing the structure might also download and read the file?

Basically, the reason behind all this is that I have a vast amount of separate files for which I would have to find a way to display in a hierarchical order for other people to view them and actually make sense of the entire structure & the files. (PS: Creating a folder structure on the computer won’t work because the names of some of the folders become too long and thus limit the maximum depth of the structure since at some point, the folder path reaches its limit.)