Retrieve a Post that has a related posts field using a searchlistbox

get-post-w-posts.curl

curl https://046a1a87-api.agilitycms.cloud/fetch/en-us/item/15?contentLinkDepth=1 
--header "APIKey: defaultlive.2b7f3a91559d794bedb688358be5e13af2b1e3ae8cd39e8ed2433bbef5d8d6ac"
{
  "contentID": 15,
  "properties": {
    "state": 2,
    "modified": "2019-08-15T16:22:34.45",
    "versionID": 165,
    "referenceName": "posts",
    "definitionName": "Post",
    "itemOrder": 0
  },
  "fields": {
    "title": "How this site works!",
    "author": {
      "contentID": 25,
      "properties": {
        "state": 2,
        "modified": "2019-08-14T13:07:25.99",
        "versionID": 142,
        "referenceName": "postauthors",
        "definitionName": "Author",
        "itemOrder": 0
      },
      "fields": {
        "name": "James Vidler",
        "image": {
          "label": null,
          "url": "https://046a1a87-cdn.agilitycms.cloud/Attachments/NewItems/P6150353_small_20190814170433_0.jpg",
          "target": null,
          "filesize": 26738,
          "pixelHeight": "433",
          "pixelWidth": "577",
          "height": 433,
          "width": 577
        }
      }
    },
    "authorID": "25",
    "details": "<p>Here is some dummy content for the post details...</p>",
    "relatedPostsIDs": "27,16",
    "relatedPosts": [
      {
        "contentID": 16,
        "properties": {
          "state": 2,
          "modified": "2019-08-15T16:28:01.053",
          "versionID": 167,
          "referenceName": "posts",
          "definitionName": "Post",
          "itemOrder": 1
        },
        "fields": {
          "title": "How to handle SEO with a JS app",
          "image": {
            "label": null,
            "url": "https://046a1a87-cdn.agilitycms.cloud/Attachments/NewItems/jamstack-acronym_20190326190136_0.png",
            "target": null,
            "filesize": 67338,
            "pixelHeight": "660",
            "pixelWidth": "966",
            "height": 660,
            "width": 966
          },
          "details": "<p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>"
        },
        "seo": null
      },
      {
        "contentID": 27,
        "properties": {
          "state": 2,
          "modified": "2019-08-14T17:12:07.21",
          "versionID": 161,
          "referenceName": "posts",
          "definitionName": "Post",
          "itemOrder": 2
        },
        "fields": {
          "title": "Sample post",
          "author": { "contentid": 26 },
          "authorID": "26",
          "details": "<p>Sample content for sample post</p>"
        },
        "seo": null
      }
    ]
  }
}