{
  "filters": {
    "and": [
      {
        "string_equals": {
          "fields": [
            "collectionCode"
          ],
          "value": "pal"
        }
      },
      {
        "string_equals": {
          "fields": [
            "associatedMedia.category"
          ],
          "value": "specimen"
        }
      },
      {
        "exists": {
          "fields": [
            "associatedMedia"
          ]
        }
      }
    ]
  }
}