The Wikipedia page on the White House’s Executive Residence has lots of details and floor plans.
The rooms of the Second Floor of the Executive Residence, containing the private living apartments of the First Family, were rebuilt largely as they had been, but provided with built-in closets and additional bathrooms. So there’s a bit of the Ship of Theseus conundrum as to whether the current rooms are the same rooms as the pre-Truman reconstruction rooms!
On the Second Floor of the Executive Residence, there are a number of bedrooms that currently serve, or have served, as bedrooms. A couple of them - the Lincoln Bedroom and the Queens’ Bedroom - are considered historic. They are currently used as guest rooms, and have never been bedrooms of Presidents.
The other rooms, in which the First Family live, are not considered historic, and may be redecorated or undergo architectural revision at the whim of the President.
The President’s traditional sleeping area - The Presidential Suite - consists of three principal rooms, all of which have served as bedrooms at one time or another. In recent years, at least from the Fords until the Obamas, these rooms have been used for the same purposes: President’s bedroom, private sitting room, and dressing room.
The bedroom - the largest room - has usually been used by the President and First Lady as their private bedroom, going all the way back from second President John Adams to President Obama. Several Presidents, however, including Lincoln, Wilson, Harding, FD Roosevelt, Truman, Eisenhower, Kennedy and Nixon slept in the smaller room that is now the sitting room. President Ford turned this smaller bedroom into a study and living room, and it has served this role until at least 2013.
Several Presidents and their wives have had separate bedrooms, including, in more recent years, the Kennedys, Johnsons and Nixons (and Clinton temporarily slept on a sofa in an adjacent room in 1998). Donald Trump is apparently the latest to do so, as he and his wife reportedly sleep in separate rooms at the White House, although its not known which rooms these are.
So, in conclusion, we know that President Obama, and his wife, slept in the large President’s bedroom, but we will probably have to wait until some future Administration to find out the exact sleeping arrangements of the current occupant of the White House.