Building a GROQ query programmatically for a hierarchical route schema.

*[
  slug.current == $slug[2] &&
  parentPage->slug.current == $slug[1] &&
  parentPage->parentPage->slug.current == $slug[0]
 ]

{
  "slug": ["/","parent", "page"]
}

$slug[] { "slug" : ^ }

export default {
  name: "route",
  type: "document",
  title: "Route",
  icon: LinkIcon,
  fields: [
    {
      name: "parentPage",
      type: "reference",
      to: {
        type: "route",
      },
    },
    {
      name: "slug",
      type: "slug",
      title: "Slug",
    },
  ]
}

const slug = [null, 'parent', 'page']
const parentPageSelector = `parentPage->`;
const idQuery = slug
    .map(
        (_segment, index, slug) =>
            `${parentPageSelector.repeat(index)}slug.current == $slug[${slug.length - 1 - index}]`
    )
    .join('&& \n');

const query = `*[${idQuery}]`;