group_vars-all

env_devmgmt_name: "devmgmt"
env_mgmt_name: "mgmt"
env_preprod_name: "preprod"
env_prod_name: "prod"

meta-main.yml

---
dependencies:
  - { role: aws.find-subnets, subnet_code_name: "pub_1" }
  - { role: aws.find-subnets, subnet_code_name: "pub_2", when: env == env_mgmt_name }
  - { role: aws.find-subnets, subnet_code_name: "be_1" }
  - { role: aws.find-subnets, subnet_code_name: "be_2", when: env == env_mgmt_name }
  - { role: aws.find-subnets, subnet_code_name: "be_deploy", when: env == env_mgmt_name }
  - { role: aws.find-vpc }
  - { role: aws.find-vpc, myenv: "preprod" }
  - { role: aws.find-vpc, myenv: "prod" }
  - { role: aws.find-vpc, myenv: "devenvs", when: env == env_devmgmt_name }
  - { role: aws.find-sg, sg_name: "pub_jump"}

Playbook.yml

---
- hosts: localhost

  vars:
    env: "{{ env_devmgmt_name }}"

  roles:
    - aws/create

roles-aws-create-main.yml

- name: "Launch instance for jumpbox: {{ owner }}_i_{{ env }}_jump_1"
  ec2:
    region: "{{ region }}"
    image: "{{ ami_id }}"
    count_tag:
      Name: "{{ owner }}_i_{{ env }}_jump_1"
    exact_count: 1
    wait: yes
    instance_type: "t2.micro"
    key_name: "{{ ssh_key_name}}"
    group_id:
      - "{{ {{ env }}_sg_pub_jump.group_id }}"
      - "{{ sg_ssh.group_id }}"
    vpc_subnet_id: "{{ subnet_pub_1.id }}"
    zone: "{{ az1 }}"
    instance_tags:
      Name: "{{ owner }}_i_{{ env }}_pub_jump_1"
      Env: "{{ owner }}_{{ env }}"
      Tier: "{{ owner }}_{{ env }}_pub"
  register: i_jump_1

"env" is defined at the start of my Playbook.yml. The actual value is from group_vars/all, but it could be even written verbatim in the Playbook.yml,it doesn't matter.

obviously.

not asking what {{env}} is, asking what the format is of the dicts, and where they're set

otherwise it's unclear what's being interpolated, and what's just a string.