{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/column-formatting.schema.json",
  "elmType": "a",
  "txtContent": "@currentField",
  "attributes": {
    "href": {
      "operator": "+",
      "operands": [
        "'../",
        "@currentField"
      ]
    },
    "target": "_blank"
  }
}