db={"users":[{"_id":1,"username":"test 1","environtmentId":1},{"_id":2,"username":"test 2","environtmentId":2},{"_id":3,"username":"test 3","environtmentId":2}],"workspaces":[{"_id":1,"name":"workspace 1"},{"_id":2,"name":"workspace 2"},{"_id":3,"name":"workspace 3"}],"environtments":[{"_id":1,"name":"env 1","workspaceId":1},{"_id":2,"name":"env 2","workspaceId":2}]}

db.users.aggregate([{"$lookup":{"from":"environtments","localField":"environtmentId","foreignField":"_id","as":"environtmentId"}},{"$unwind":{"path":"$environtmentId","preserveNullAndEmptyArrays":true,},},{"$lookup":{"from":"workspaces","localField":"workspaceId","foreignField":"environtmentId._id","as":"environtmentId.workspaceId"}},{"$unwind":{"path":"$environtmentId.workspaceId","preserveNullAndEmptyArrays":true,},}])