How to create Categories and its SubCategory in Prisma ORM using MongoDB

type Category {
  id: ID! @id
  name: String!
}

type SubCategoryLevel1 {
  id: ID! @id
  name: String!
  parentCategory: Category! @relation(link: INLINE)
}

type SubCategoryLevel2 {
  id: ID! @id
  name: String!
  parentCategory: SubCategoryLevel1! @relation(link: INLINE)
}

What if my Category levels are not decided, I'm using Prisma ORM and MongoDB.

Not sure I correctly understand your question. Could you go into a bit more detail what you are trying to do?

Are you trying to do arbitrarily deeply nested self-relations? Then you can do something like this:

type Category {
  id: ID! @id
  name: String!
  subCategory: Category @relation(name:"SubToParent"link: INLINE)
  parentCategory: Category @relation(name: "SubToParent")
}

Creating three levels would work with this query:

mutation createCategory {
  createCategory(
    data: {
      name: "firstLevel"
      subCategory: {
        create: {
          name: "secondLevel"
          subCategory: { create: { name: "thirdLevel" } }
        }
      }
    }
  ) {
    name
  }
}

And querying for categories would give you this response:

query allCategories {
  categories {
    name
    subCategory {
      name
    }
    parentCategory {
      name
    }
  }
}

{
  "data": {
    "categories": [
      {
        "name": "firstLevel",
        "subCategory": {
          "name": "secondLevel"
        },
        "parentCategory": null
      },
      {
        "name": "secondLevel",
        "subCategory": {
          "name": "thirdLevel"
        },
        "parentCategory": {
          "name": "firstLevel"
        }
      },
      {
        "name": "thirdLevel",
        "subCategory": null,
        "parentCategory": {
          "name": "secondLevel"
        }
      }
    ]
  }
}

I hope that helps, if not just explain your question in a bit more detail.