gistfile1.txt

$ ansible --version
ansible 2.9.11
  config file = None
  configured module search path = ['/home/user/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.6/dist-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.6.9 (default, Jul 17 2020, 12:50:27) [GCC 8.4.0]
  
$ pip list | grep jmespath
jmespath              0.10.0

$ pip list | grep Jinja2
Jinja2                2.11.2

$ cat test.yml 
---
- hosts: localhost
  gather_facts: false

  vars:
    "nvme_output":
      stdout: {
            "Devices": [
                {
                    "DevicePath": "/dev/nvme0n1",
                    "Firmware": "1.0",
                    "Index": 0,
                    "MaximumLBA": 33554432,
                    "ModelNumber": "Amazon Elastic Block Store",
                    "PhysicalSize": 17179869184,
                    "ProductName": "Non-Volatile memory controller: Vendor 0x1d0f Device 0x8061",
                    "SectorSize": 512,
                    "SerialNumber": "vol0e6af89fd1991cwtf",
                    "UsedBytes": 0
                },
                {
                    "DevicePath": "/dev/nvme1n1",
                    "Firmware": "1.0",
                    "Index": 1,
                    "MaximumLBA": 104857600,
                    "ModelNumber": "Amazon Elastic Block Store",
                    "PhysicalSize": 53687091200,
                    "ProductName": "Non-Volatile memory controller: Vendor 0x1d0f Device 0x8061",
                    "SectorSize": 512,
                    "SerialNumber": "vol0885625da4a60awtf",
                    "UsedBytes": 0
                }
            ]
        }

  tasks:
    - debug:
        var: nvme_output.stdout
    - debug:
        msg: "{{ nvme_output.stdout | json_query('Devices[*].DevicePath') }}"

$ ansible-playbook test.yml 
[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

PLAY [localhost] ****************************************************************************************************************************************************************************************************************************

TASK [debug] ********************************************************************************************************************************************************************************************************************************
ok: [localhost] => {
    "nvme_output.stdout": {
        "Devices": [
            {
                "DevicePath": "/dev/nvme0n1",
                "Firmware": "1.0",
                "Index": 0,
                "MaximumLBA": 33554432,
                "ModelNumber": "Amazon Elastic Block Store",
                "PhysicalSize": 17179869184,
                "ProductName": "Non-Volatile memory controller: Vendor 0x1d0f Device 0x8061",
                "SectorSize": 512,
                "SerialNumber": "vol0e6af89fd1991cwtf",
                "UsedBytes": 0
            },
            {
                "DevicePath": "/dev/nvme1n1",
                "Firmware": "1.0",
                "Index": 1,
                "MaximumLBA": 104857600,
                "ModelNumber": "Amazon Elastic Block Store",
                "PhysicalSize": 53687091200,
                "ProductName": "Non-Volatile memory controller: Vendor 0x1d0f Device 0x8061",
                "SectorSize": 512,
                "SerialNumber": "vol0885625da4a60awtf",
                "UsedBytes": 0
            }
        ]
    }
}

TASK [debug] ********************************************************************************************************************************************************************************************************************************
ok: [localhost] => {
    "msg": [
        "/dev/nvme0n1",
        "/dev/nvme1n1"
    ]
}

PLAY RECAP **********************************************************************************************************************************************************************************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0