Add group based on domainname if found

roles/base/tasks/main.yml

@@ -1,4 +1,10 @@
 ---
+- name: Group by domainname
+  ansible.builtin.group_by:
+    key: "{{ inventory_hostname.split('.')[1] }}"
+  changed_when: false
+  when: inventory_hostname | split('.') | length == 4
+
 - name: Setup ansible custom facts
   ansible.builtin.file:
     dest: "{{ item }}"