Hello guys

got one product which is available as download, but the download file is far too big so I want to split it up in few parts.
Basically what I want is :
- customer purchase one product
- after purchase, customer see the order in the order history (as usual) BUT customer have multiple buttons to download the different parts of what they purchased

I know how to setup products with one download, but did not found a way to add multiple download ... to be clear, all the download on this product should be accessible to the customer (it's not about choosing one option among few).

How to set up such an option in the admin ?

thanks