Hiera lookup on array of hashes, is it possible?

edit

Hello, I am not sure if this is possible at all, but let me introduce with challenge I am experiencing. I have this configuration:

cloud::provision:
  'strname':
    key1: str1
    key2: str2
    sg_key:
      -
        protocol: 'tcp'
        port: '1111'
        cidr: '172.31.0.0/16'
      -
        protocol: 'tcp'
        port: '2222'
        cidr: '172.31.0.0/16'
      -
        protocol: 'tcp'
        port: '3333'
        cidr: '172.31.0.0/16'

So, I have a lot of these rules (array of hashes) for every security group for every EC2 instance on AWS. I want to simplify whole process and make a lookup like this:

common.yaml

lookupkey:
      -
        protocol: 'tcp'
        port: '1111'
        cidr: '172.31.0.0/16'
      -
        protocol: 'tcp'
        port: '2222'
        cidr: '172.31.0.0/16'
      -
        protocol: 'tcp'
        port: '3333'
        cidr: '172.31.0.0/16'

and have this:

cloud::provision:
  'strname':
    key1: str1
    key2: str2
    sg_key: "%{hiera('lookupkey')}"

Doing a lookup from CLI (first example), I am getting this response:

{"strname"=>
  {"key1"=>"str1",
   "key2"=>"str2",
   "sg_key"=>
    [{"protocol"=>"tcp", "port"=>"1111", "cidr"=>"172.31.0.0/16"},
     {"protocol"=>"tcp", "port"=>"2222", "cidr"=>"172.31.0.0/16"},
     {"protocol"=>"tcp", "port"=>"3333", "cidr"=>"172.31.0.0/16"}]}}

If I try to do a lookup in second example (with hiera lookup), I am getting this:

{"strname"=>
  {"key1"=>"str1",
   "key2"=>"str2",
   "sg_key"=>
"[{\"protocol\"=>\"tcp\", \"port\"=>\"1111\", \"cidr\"=>\"172.31.0.0/16\"}, {\"protocol\"=>\"tcp\", \"port\"=>\"2222\", \"cidr\"=>\"172.31.0.0/16\"}, {\"protocol\"=>\"tcp\", \"port\"=>\"3333\", \"cidr\"=>\"'172.31.0.0/16\"}]"}}

Is it possible to get non-escaped output? Is this possible at all? It's very uncomfortable to have over 300 instances and have to change SG rules one by one instead on the one place. Thanks.