playbook.yml

- hosts: all
  sudo: yes
  vars_files:
    - [ "vars/${inventory_hostname}/projects.yml", "vars/projects.yml" ]

  tasks:
  - include: tasks/projects.yml

tasks projects.yml

# tasks
---
- include: tasks/test.yml
  with_items: $projects

- name: test
  debug: msg="$item"
  with_items:
    $projects

tasks test.yml

# tasks
---
- name: debug
  debug: msg="$item"

vars projects.yml

# variable
---
projects:
  - name: Frist proj
    domain: first.com
  - name: Second proj
    domain: second.com