The scenario for determining to qualify for the Champions League in this way will not benefit Dortmund even though they still have a chance. Frankfurt, Freiburg and Dortmund will fight to get a ticket to the Champions League which is determined in the last match. Dortmund will not be too difficult in this match because they will face Kiel as the bottom of the relegation zone. A big win needs to be achieved by Dortmund because if Frankfurt's match against Freiburg ends in a draw it will benefit them.
If the Frankfurt vs Freiburg match ends in a draw, then the one who is more detrimental is the Freiburg team if Dortmund can win at home today. So this last match will be really tough for all teams, especially for the three teams you mentioned and I am quite sure that Dortmund will fight to win today's match because there is one place that Dortmund can get through the Freiburg vs Frankfurt match results. However, if Freiburg wins today's match, it will be very painful for Dortmund because the Dortmund team must be able to exceed the number of goals difference that Frankfurt currently has so Dortmund must be able to win with more goals in this last match.