support for downloading files with many parts

For example if a 2GB file is split into parts of 350 mb
look like this:
parte1.rar
parte2.rar
parte3.rar

And if each part is located in more than one server
The program should download each part only once and the most convenient way
Thanks for all

Would it be possible to add a button called "add part"?

And that the resulting dialog box serves to put all the links that correspond to that part of the file.