Salaam Aleikum,
As far as I know, if one wishes to pray the nafilah prayers for Dhuhr and Asr, then he/she should begin with nawafil Dhuhr, Dhuhr, nawafil Asr, then Asr. However, I was wondering if it is possible to first pray Dhuhr and Asr, then Nafilah Dhuhr and Nafilah Asr. That is because I heard that we should pray the wajib prayers before the Nafilah.
Thank you all, and may Allah bless you.