I have some qaza namaz like of around X days and in this holy month of Ramadan, I am praying namaz e shab. So praying my qaza namaz in nafela’s place. So can I pray 2 maghrib and 1 fajr to make 8 Rakat or and normally situations can I pray 2 magrib and dhohar together?

That’s great you can pray qadha at namaz e Shab but the method and order you have mentioned is incorrect you must follow the order like dhuhr and Asr, maghrib and isha