javascript - Mongo/Mongoose - markModified not working -

i have following query:

  section.find({"clause": sub.section}, function(err, docs){     var detail = parseint(sub.detail);     docs[0].subclauses[0].additionaldetails[detail-1].percentile = sub.percentile;     docs[0].markmodified("subclauses");     docs[0].save(function(err, doc){       if(err) { return callback(err) };        callback();     })   }) 

when log doc inside .save function appears have saved successfully. on querying db elsewhere save has not happened. object trying save 3 deep this:

[   {   "clause": "1",   "subclauses:     [      {      "clause":"1.1",      "additionaldetails:       [         {         "detail": "1",         "content": "whatever"          }       ]     }   ]    } ] 

with several items inside each array.

am not able save data nested array object using mongo?

if understand trying do, think wanting use mongo position operator ($). used index nested arrays in document. in current code referencing first object in array. using position operator able reference other positions based of other data, such query.

here documentation operator: http://docs.mongodb.org/manual/reference/operator/update/positional/

and here stack overflow response may bit also: mongodb $ operator