#!/usr/bin/perl

use strict;
use warnings;

my $perl_datastructure = {
        ...
    };


sub finder {
    my ($search,$p)= @_;
    return(@$p) if ($search eq '' and ref $p eq 'ARRAY'); 
    return($p) if ($search eq ''); 
    $p= $perl_datastructure if (not defined $p);
    
    if (ref $p eq 'HASH') {
        $search=~ s/^(.*?)(->|$)//;
        my $bit=$1; 
        return finder($search,$p->{$bit}) if (exists $p->{$bit});
        return();
    }
    
    if (ref $p eq 'ARRAY') {
        my @results=();
        foreach my $a ( @$p ) {
            push @results, finder($search,$a);
        }
        return @results;
    }

    #here should be error messages or further 
    #code to handle refs and scalars
}

print join(' ',finder('Root->PersonA->Pets')),"\n";

print join (" ",finder('Root->PersonB->Pets')),"\n";

##</code><code>##

PetA PetB
PetAA PetBB