I have write below query in GraphQL but it returing error

query {
pageCollection(limit: 10) {
items {
  contentSectionCollection(limit: 5) {
    items {
      heading
      subSectionCollection(limit: 5) {
        items {
          ... on Link {
            name
            url
          }
          ... on MenuItems {
            itemName
            itemLink
          }
        }
      }
    }
  }
 }}}

I am getting the following error message when I execute this query:

“message”: “Query execution error. Link from entry ‘2a5FbawGI23CVMfzwh6r7k’ to entry ‘2ckO708SEG6Z8X1TzVJS0V’ on field ‘subSection’ within type ‘Section’ returned an unexpected content type”,

I need to return two types of data in the subSectionCollection. Sometimes it may have only one value, and other times it may have both values.