Sometimes they make an extra Sajdah after reading Tashahhud and Durood and there, they ask for any specific Du’a they are in need for. They even call this Salah as Hajat. However I have not come across any kind of this Salah in the Hadith.
A: Haamidaw wa Musalliyaa
Making more than two Sajda's in one Rakat, except for any Sajda-e-Tilaawat or Sajda-e-Sahw is not established in any Salah. If the Sajda you refer to is a part of the Salah then this is an incorrect practice. Reciting the same Surah a number of times in one Rakat has been established in some traditions.
And Allah Ta'ala Knows Best
Shafiq Jakhura (Mufti)