using only rar:

I don’t know how to do it with any GUI, but from the command line it’s easy.
Open a terminal and use this command:

rar a -r -m3 -v5g archivename path/to/folder/that/you/want/to/split


a = add files to archive

r = recursive, you need this if the folder you want to split has subfolders.

m3 = medium compression, use 0 for no compression, 5 for best compression. Adjust as desired.

v = multivolume (split)

5g = 5 GB per volume. Adjust number as desired. Use m for MB for smaller jobs.

archivename = the name you want the archive to be called. If you don’t specify a path here, the archive will be placed in whatever directory the terminal is in (probably your /home)

path/to/folder/that/you/want/to/split = self explanatory 🙂

All this is explained in the rar man page. Rar can do tons of stuff from the command line. In a terminal:man rar