Let’s say you want to play a C4 with its 5th, G. Normally, on the same octave, G4 is 7 semitones above, and on the octave below G3 is 5 semitones below.
A4 uses 7 semitones below, for me it’s a fourth (F3).
A workaround to get a fifth (above) is to increase osc by 7 semitones, C4 become G4, F3 become C4, and now you have a fifth with C as root note.
On the second osc you can increase osc by 10 semitones (with 5th sub on), and you get a Cm7 chord.
Chart for making chords with osc's - #7 by sezare56