Doctor Strange basically took place during Captain America: Civil War, so he likely will be relatively new in his position during Thor: Ragnarok.
According to this statement, Thor: Ragnarok takes place “a couple years” after Ultron.
So [Thor: Ragnarok] happens maybe on top of Civil War, on top of Spider-Man [Homecoming].
At one point, Captain America: Civil War directors Joe Russo and Anthony Russo say that their movie takes place about a year after the events of Avengers: Age of Ultron.