my @stuff;

while (<DATA>)
{
    my @fields = split $Delimiter, $_;

    my ($type, $name) = $fields[0] =~ /^(...)(.*)/;

    if ($type eq 'BNA')
    {
        # I don't know what other data you want to keep from the BNA line ...
        push @stuff, {
            name => $name,
            products => [],
        };

        next;
    }

    # I don't know what you want to do with this, so I'll just keep it there.
    push @{$stuff[-1]{products}}, $_;
}