how to export nested JSON Value

"Signature": [
                            {
                              "Id": "signature",
                              "Object": [
                                {
                                  "QualifyingProperties": [
                                    {
                                      "Target": "signature",
                                      "SignedProperties": [
                                        {
                                          "Id": "id-xades-signed-props",
                                          "SignedSignatureProperties": [
                                            {
                                              "SigningTime": [
                                                {
                                                  "_": "2024-07-10T07:26:32Z"
                                                }
                                              ],
                                              "SigningCertificate": [
                                                {
                                                  "Cert": [
                                                    {
                                                      "CertDigest": [
                                                        {
                                                          "DigestMethod": [
                                                            {
                                                              "_": "",
                                                              "Algorithm": "http://www.w3.org/2001/04/xmlenc#sha256"
                                                            }
                                                          ],
                                                          "DigestValue": [
                                                            {
                                                              "_": "SLFswNMf8a6muzczA+EO356bvJNDkr9LhT25+pqacdE="
                                                            }
                                                          ]
                                                        }
                                                      ],
                                                      "IssuerSerial": [
                                                        {
                                                          "X509IssuerName": [
                                                            {
                                                              "_": "CN=Trial LHDNM Sub CA V1, OU=Terms of use at http://www.posdigicert.com.my, O=LHDNM, C=MY"
                                                            }
                                                          ],
                                                          "X509SerialNumber": [
                                                            {
                                                              "_": 352825
                                                            }
                                                          ]
                                                        }
                                                      ]
                                                    }
                                                  ]
                                                }
                                              ]
                                            }
                                          ]
                                        }
                                      ]
                                    }
                                  ]
                                }
                              ],