The third entry - There was probably a passage from the palace to the temple at this entry, and the meeting would take place in some private chamber close by.
Related Commentaries of Jeremiah 38:14
Jeremiah 38:14
14 Then Zedekiah the king sent, and took Jeremiah the prophet unto him into the thirdd entry that is in the house of the LORD: and the king said unto Jeremiah, I will ask thee a thing; hide nothing from me.