gistfile1.txt

> db.foo.aggregate([{$unwind: '$sub'}, {$match: {start: {$lte: 3}, end: {$gte: 6} }}])
{
  "result" : [
		{
			"_id" : ObjectId("522da57d186b82d5279cb35c"),
			"start" : 3,
			"end" : 6,
			"sub" : {
				"start" : 3,
				"end" : 6
			}
		},
		{
			"_id" : ObjectId("522da57d186b82d5279cb35c"),
			"start" : 3,
			"end" : 6,
			"sub" : {
				"start" : 6,
				"end" : 7
			}
		}
	],
	"ok" : 1
}