I’m sorry, but that is incorrect. All one needs to do is completely read Daniel 6 and Daniel 14 and one will come to the understanding that they are two seperate events. One event tells of how Daniel was cast into the lions den for one night for transgressing King Darius the Mede’s edict. The second event was when Daniel was thrown into the lion’s den for 6 days for proving to a different king, from a different empire (Babylon), that the priests were frauds AND for killing the dragon whom the Babylonians worshipped.
Daniel at the time of the overthrow of Babylon would have been at least 70 years old so when did these events occur? Who was this “different king”? Cambyses II? His brother? Nidintu-Bel? And when did these event occur in Daniel's life?
As I'm sure you know, The History of Susanna plus Bel and the Dragon are not part of the Hebrew Bible canon so they cannot be chapters in the book of Daniel.