Database

[{"_id":{"$oid":"664baf560b9539e48fbc6ed1"},"name":"first assignment","next":{"$oid":"664baf620b9539e48fbc6ed2"},"preview":null,"date":{"$date":"2024-04-20T10:00:00.000Z"}},{"_id":{"$oid":"664baf620b9539e48fbc6ed2"},"name":"second assignment","next":{"$oid":"664baf6d0b9539e48fbc6ed3"},"preview":{"$oid":"664baf560b9539e48fbc6ed1"},"date":{"$date":"2024-04-21T10:00:00.000Z"}},{"_id":{"$oid":"664baf6d0b9539e48fbc6ed3"},"name":"third assignment","next":{"$oid":"664baf8d0b9539e48fbc6ed4"},"preview":{"$oid":"664baf620b9539e48fbc6ed2"},"date":{"$date":"2024-04-22T10:00:00.000Z"}},{"_id":{"$oid":"664baf8d0b9539e48fbc6ed4"},"name":"fourth assignment","next":null,"preview":{"$oid":"664baf6d0b9539e48fbc6ed3"},"date":{"$date":"2024-04-23T10:00:00.000Z"}}]

Query

db.collection.aggregate([{"$match":{/** id of 4th assignment*/"_id":{"$oid":"664baf8d0b9539e48fbc6ed4"}}},{$set:{next:{/** id of 5th assignment*/"$oid":"664baf8d0b9539e48fbc6ed5"}}},{"$unionWith":{"coll":"collection","pipeline":[{"$documents":[/** 5th assignment here*/{"_id":{"$oid":"664baf8d0b9539e48fbc6ed5"},"name":"fifth assignment","next":null,"preview":{/** id of 4th assignment*/"$oid":"664baf8d0b9539e48fbc6ed4"},"date":"$$NOW"}]}]}},{"$merge":{"into":"collection","on":"_id"}}])

Result