You can construct a reference to a hash of hashes all in one go. The variable $rhEnvInfo below will hold a reference to the hash keyed by environment name and whose values are references to further hash tables containing information for each environment. Values for a particular environment can be accessed by de-refencing with the -> operator. Like this

use strict;
use warnings;

my $rhEnvInfo =
   {
      LIVE  => {ADMIN_DIR => q{/opt/bin1}},
      DEVLP => {ADMIN_DIR => q{/opt/bin2}},
      TEST  => {ADMIN_DIR => q{/opt/bin3}}
   };

my $try = q{DEVLP};

print
   qq{ADMIN_DIR for $try is },
   qq{$rhEnvInfo->{$try}->{ADMIN_DIR}\n};
[download]

When run this prints

ADMIN_DIR for DEVLP is /opt/bin2
[download]

I hope this helps.

Cheers,

JohnGG