use strict;
use XML::Rules;

sub do_something_with {
	print join(', ', @_), "\n";
}

my $parser = XML::Rules->new(
	rules => {
		_default => 'content',
		asset => 'as array no content',
		account => sub {
			my ($tag, $attr) = @_;
			foreach my $asset (@{$attr->{asset}}) {
				do_something_with($attr->{accountId}, $attr->{accountName}, $asset->{assetId}, $asset->{assetName});
			}			
		},
	}
);

$parser->parse(\*DATA);

__DATA__
<data>
<account>
    <accountId>001</accountId>
    <accountName>Account 001</accountName>
    <asset>    
        <assetId>abcd</assetId>
        <assetName>Asset abcd</assetName>
    </asset>
 ...