The Data::Search module is a perfect fit for your problem.

Working, tested code:

use strict;
use warnings;
use Data::Search;
use Data::Dumper; $Data::Dumper::Useqq=1; $Data::Dumper::Terse=1;

my $href = {
  foo => {
    child1 => { gchild1 => { values => { bar1 => 1, bar2 => 1 } } },
    child2 => {
                gchild1 => { values => { bar1 => 1, bar9 => 1 } },
                gchild2 => { values => { bar2 => 1, bar3 => 1 } },
    },
    child3 => {              values => { bar1 => 1, bar2 => 1, bar4 =>
+ 1, bar5 => 1 } },
  },
};

for my $wanted ( qw( bar5 bar3 bar2 ) ) {
    my @results = datasearch(
        data   => $href,
        search => 'keys',
        find   => qr{ \A $wanted \z }msx,
        return => 'container',
    );

    print "Found key '$wanted' in these hashrefs: ", Dumper @results;
}
[download]

Output:

Found key 'bar5' in these hashrefs: {
  "bar1" => 1,
  "bar4" => 1,
  "bar2" => 1,
  "bar5" => 1
}
Found key 'bar3' in these hashrefs: {
  "bar2" => 1,
  "bar3" => 1
}
Found key 'bar2' in these hashrefs: {
  "bar2" => 1,
  "bar3" => 1
}
{
  "bar1" => 1,
  "bar4" => 1,
  "bar2" => 1,
  "bar5" => 1
}
{
  "bar1" => 1,
  "bar2" => 1
}