You need a function that compares two strings and returns "TRUE" if they are sufficiently similar and "FALSE" otherwise. In general, this is impossible. We must settle for a function that is good enough. We determine "good enough" by testing. Only you can determine how much testing is required. I doubt that your example of one match and several mismatches is sufficient. Here is a sample of test code using a match and a mismatch from your test cases. I have provided my first attempt (special_match) at you function to get you started.

use strict;
use warnings;
use Test::More tests=>2;

my $should_match = 1;
my $should_not_match = 0;
my @cases = (
    ['ON_DIE_FILLER/filler_fuse',
     'die0_ON_DIE_FILLER_ON_DIE_FILLER_filler_fuse',
     $should_match,
    ],
    ['ON_DIE_FILLER/filler_fuse',
     'die0_ON_DIE_FILLER_ON_DIE_FILLER_filler_byte',
     $should_not_match,
    ],
);

foreach my $case (@cases) {
    if ($case->[2] == $should_match) {
            ok( special_match($case->[0], $case->[1]), $case->[1]);
        }
        else {
            ok( !special_match($case->[0], $case->[1]), $case->[1]);
        }
}

sub special_match {
    my ($s1,$s2) = @_;
    $s1 =~ tr{/}{_};        # fix separator
    return $s2 =~ m/$s1$/;  # $s1 at end of $s2

}


OUTPUT:

1..2
ok 1 - die0_ON_DIE_FILLER_ON_DIE_FILLER_filler_fuse
ok 2 - die0_ON_DIE_FILLER_ON_DIE_FILLER_filler_byte
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