Multi Level Grouping

Hi is it possible to get multi-level grouping information. As right now we are able to group based on one field but instead group on multiple fields simultaneously.
"group_key1":{
"sub_group_key1":{

  },

"sub_group_key2":{

  }

},
"group_key2":{
"sub_group_key1":{

  },

"sub_group_key2":{

  }

}.

Also currently if you group across a field you get at max 10 results per group (1 most matched and 9 under _group key) Is it possible to get all the results of a particular group

Unfortunately, neither are possible right now.