change-nested-dict-key-value-ansible

---
- hosts: localhost
  connection: local
  gather_facts: no

  vars:
    dict_one:
      dict_two:
        variables:
          test: please-change-me # <-- I want to just change this variable.
          another: value
      dict_four:
        test: another unique example

  tasks:
    - name: Change dict_one.dict_two.variables.test to "changed".
      set_fact:
        dict_one_changes: "{{ dict_one.dict_two.variables|combine({'test': 'changed'}) }}"

    - debug: var=dict_one_changes
    # "dict_one_changes": {
    #   "another": "value",
    #   "test": "changed"
    # }

    - name: Merge changes back into dict_one.
      set_fact:
        dict_one: "{{ dict_one|combine(dict_one_changes) }}"

    - debug: var=dict_one
    # "dict_one": {
    #   "another": "value",
    #   "dict_four": {
    #     "test": "example to not be overridden"
    #   },
    #   "dict_two": {
    #     "variables": {
    #       "another": "value",
    #       "test": "please-change-me"
    #     }
    #   },
    #   "test": "changed" <-- combined dict change goes to root level
    # }