In accordance with US DOT §399.87: Deductibles and baggage fees:
For passengers whose origin or destination of the ticket is a US point, US and foreign carriers must apply the baggage allowances and applicable fees at the beginning of the passenger's itinerary. throughout his itinerary.
This means that the baggage allowance can not be changed throughout the trip. There must be only one baggage allowance that applies to the entire trip.
In addition, in accordance with IATA Resolution 302, the carrier's baggage policy marketing the most significant route (the first to cross continental "zones", in this case the BOS segment -DOH) applies to the entire trip.
In this case, the marketing carrier of this flight is Qatar Airways (this flight being referred to as a QR flight on your booking confirmation) and their travel policy to and from the United States is two 23 kilogram free bags.
Therefore, for your entire itinerary, you should be allowed to register two free bags weighing up to 23 kg each.