Nintendo have placed Tri Force Heroes on the official Legend of Zelda timeline, positioning it some time after A Link Between Worlds. The official Japanese Zelda Twitter account shared a timeline featuring the games and ports released during and since 2011.
Hyrule Historia, first published in December 2011, established the official timeline, which confirmed a previous fan theory about the timeline splitting after the events of Ocarina of TIme. This timeline was published before A Link Between Worlds and Tri Force Heroes were released.
The Tri Force Heroes developers had commented on its position in the timeline in October 2015, in which they clarified “the game takes place several years after A Link Between Worlds and features the same hero.” They also added that “the player character you control is the true Hyrulian hero.”