Database
[{"_id":ObjectId("5f281caf3494701c38711e96"),"WidgetId":"0233261","Specs":[{"WidgetType":"A","AmountLow":NumberLong(0),"AmountHigh":NumberLong(0)},{"WidgetType":"A","AmountLow":NumberLong(0),"AmountHigh":NumberLong(500)},{"WidgetType":"A","AmountLow":NumberLong(1),"AmountHigh":NumberLong(1000)}]}]
Query
db.collection.find({Specs:{$elemMatch:{AmountLow:0,AmountHigh:{$gt:0}}}},{_id:1,WidgetId:1,"Specs.$":1})