The D Harmonic Minor scale uses the same fingering as the C major scale but contains one sharp (C sharp) and one flat (Bb) . Just like previous scales it’s best to try 1 and 2 octave hands separately before trying the scale hands together. You can increase it to 3 and 4 octaves by putting the thumb under again in the right hand and 4th in the left hand and continuing the same finger pattern further up the piano. The Melodic minor (which has a B natural and C# going up) and the Natural minor (which has a C natural and Bb) are typically used in conjunction which each other playing the ascending Melodic minor going up the piano followed by the Natural minor going down the piano. The D minor scale is included in the earlier grades with 2 octaves hands separate and together. However in more advanced grades you’ll be expected to play it up to 4 octaves hands together as well as in staccato.  You may wish to acquire a copy of the ABRSM piano scale book which is easily obtainable in local music shops in Swindon as well as online. 

Here is the piano fingering for the D Minor scales as taught in my lessons:

One octave R.H (up) 12312345 (down) 4321321

One octave L.H (up) 54321321 (down) 2312345

Two octaves R.H (up) 123123412312345 (down) 43213214321321

Two octaves L.H (up) 543213214321321 (down) 23123412312345

Watch video demonstration of the teacher playing D Minor scale (Harmonic):