use Deep::Hash::Utils qw(reach nest deepvalue);

sub hash_filter {
    my ($source, $filter) = @_;
    my %rc;

    while (my @l = reach($filter)) {
        pop @l;
        if (defined( my $source_val = deepvalue($source, @l) ) ) {
            # hint: work around nest behavior on even vs odd key count
            nest(\%rc, @l)->{ $l[$#l] } = $source_val;
        }
    }

    \%rc;
}