# small example
my $tree = {
    top => {
        inetUser => {},
        person => {
        organizationalPerson => {
            managedPerson => {
                personnel => {}, }, }, },
        application => {
            managedApplication => {}, }, },
 };

# I need to get the nodes that lead to the one I am looking for
sub explore
{
    my $node = shift;
    my $target = shift;
    my $stack = shift;

    # we found it, so we may leave...
    return $stack if $target eq $stack->[-1];
    # we keep looking...
    my $kids = scalar keys %$node;
    if ( $kids > 0 )
    {
        for my $key ( keys %$node )
        {
            push @$stack, $key;
            show( $stack );
            explore( $node->{$key}, $target, $stack, $OK );
            pop @$stack;
        }
    }
    else
    {  # leaf... no-op
    }
}

sub show { print "$_ " for @{$_[0]}; print "\n" }

# test
my $stack;
eval
{
    explore( $tree, 'personnel', [] );
    # expected result: "top person organizationalPerson managedPerson personnel ";
};
$stack = $@;
show( $stack );
__END__