A jq filter that converts an array objects with a nested array into CSV-formatted output with one row for each of the nested arrays and the common from the parent object duplicated.

nested_jq_filter.sh

#!/usr/bin/env bash
# -----------------------------------------------------------------------------
# A jq filter that converts an array objects with a nested array into
# CSV-formatted output with one row for each of the nested arrays and the 
# common from the parent object duplicated.
# -----------------------------------------------------------------------------
jq -r '.Items[] | {"Sku": .Sku} + (.Locations[]|{"WarehouseCode": .WarehouseCode, "LocationCode": .LocationCode, "Quantity": .Quantity}) | ["\(.Sku)", "\(.WarehouseCode)", "\(.LocationCode)", .Quantity] | @csv' <<-EOF
{
  "Items": [
    {
      "Sku": "1301271DKR028",
      "PrimarySku": "1301271DKR028",
      "Code": "",
      "PrimaryCode": "4045928338",
      "Locations": [
        {
          "WarehouseCode": "VRN",
          "LocationCode": "P",
          "Quantity": 1,
          "Reserve": false
        }
      ]
    },
    {
      "Sku": "1301930RIP0OS",
      "PrimarySku": "1301930RIP0OS",
      "Code": "",
      "PrimaryCode": "4048566466",
      "Locations": []
    },
    {
      "Sku": "1301615ANH00L",
      "PrimarySku": "1301615ANH00L",
      "Code": "",
      "PrimaryCode": "4047195086",
      "Locations": [
        {
          "WarehouseCode": "MEL",
          "LocationCode": "GENERAL",
          "Quantity": 1,
          "Reserve": true
        },
        {
          "WarehouseCode": "VRN",
          "LocationCode": "R",
          "Quantity": 4,
          "Reserve": false
        }
      ]
    },
    {
      "Sku": "0000000VOM00M",
      "PrimarySku": "0000000VOM00M",
      "Code": "",
      "PrimaryCode": "4048589780",
      "Locations": [
        {
          "WarehouseCode": "VRN",
          "LocationCode": "STAGING",
          "Quantity": 36,
          "Reserve": true
        },
        {
          "WarehouseCode": "VAL",
          "LocationCode": "GENERAL",
          "Quantity": 10,
          "Reserve": true
        },
        {
          "WarehouseCode": "VRN",
          "LocationCode": "T",
          "Quantity": 14,
          "Reserve": false
        },
        {
          "WarehouseCode": "MEL",
          "LocationCode": "GENERAL",
          "Quantity": 10,
          "Reserve": true
        },
        {
          "WarehouseCode": "SHO",
          "LocationCode": "GENERAL",
          "Quantity": 10,
          "Reserve": true
        },
        {
          "WarehouseCode": "LES",
          "LocationCode": "GENERAL",
          "Quantity": 17,
          "Reserve": true
        }
      ]
    }
  ]
}
EOF