Splitting a directory
To create a split ZIP archive on OS X, you would use
zip -s <size> -r <out> <in>
size is a number followed by
k, m or
out is the name of the output files without the suffix and
in is the directory you want to compress.
Splitting a ZIP file
zipsplit -n <size> <in>
size is the maximum size in bytes of the file to create and
in is the input ZIP file. Note that it doesn’t work when there is a file larger than
size contained within the original ZIP file.