I prefer Path::Tiny to handle paths for me:

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Path::Tiny;

my $path = '/abc/def/ghi';
my $climb = path($path);
my @paths = $climb;
push @paths, $climb until ($climb = $climb->parent) eq '/';
say for @paths;
[download]

File::Spec is a core module that can handle the path as well:

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use File::Spec;

my $path = '/abc/def/ghi';

my @paths = 'File::Spec'->splitdir($path);
for my $i (reverse 0 .. $#paths) {
    $paths[$i] = join '/', @paths[0 .. $i];
}
shift @paths;  # Remove the empty path.
say for @paths;
[download]

But a regex with split will work similarly:

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Path::Tiny;

my $path = '/abc/def/ghi';

my @paths = split m{(?<=.)/}, $path;
for my $i (reverse 0 .. $#paths) {
    $paths[$i] = join '/', @paths[0 .. $i];
}
say for @paths;
[download]

I used a lookbehind assertion to skip the empty path before the first slash.