use strict;
use XML::Twig;

my $sel = 'title';
my $ign = 'title/name/fnm[@letter="a"]';
my $twig = XML::Twig->new(
ignore_elts => { "$ign" => 1},
twig_roots  => { "$sel" => 1},
pretty_print => 'indented'
);

$twig->parsefile('1.xml');

$twig->print;