As a sophomore, he won the South Carolina Independent School Association (SCISA) Class 3A state title as his team's leading scorer.

[2] As a senior, he averaged 21 points, 4.5 rebounds, and 1.8 assists per game and was named South Carolina Gatorade Player of the Year for his success in basketball and academics.

[4] Nesmith did not receive offers from any high major NCAA Division I programs until he was a senior, but he began drawing more attention after an Amateur Athletic Union (AAU) tournament in Charlotte, North Carolina.

[6] In his freshman season for Vanderbilt, Nesmith assumed an important role after Darius Garland suffered a season-ending injury and Simisola Shittu underachieved.

[20] With fellow rookie teammate, Payton Pritchard, absorbing many of injured Kemba Walker's minutes, it was difficult for Nesmith to crack the regular rotation for the first few months of the season.

With injuries and Covid protocols plaguing the Celtics all season, extended absences from Marcus Smart, Kemba Walker, and other key players gave Nesmith enough opportunities to showcase not only his shooting capabilities, but also his gritty hustle and winning attitude.

[21] By April 23, 2021, coach Brad Stevens had seen enough from the rookie to warrant consistent rotation playing time to which he hovered around 20 minutes per game for the rest of the regular season.

On July 9, 2022, Nesmith was traded, alongside Daniel Theis, Malik Fitts, Juwan Morgan, Nik Stauskas and a 2023 first-round pick, to the Indiana Pacers in exchange for Malcolm Brogdon.

[27] On November 19, Nesmith scored 19 points off the bench on 5–8 three-point shooting, while making two game-winning free throws with 9.6 seconds remaining, to defeat the Orlando Magic 114–113.

[37][38] On December 30, Nesmith made a career-high 7 three-pointers in a victory over the New York Knicks, on a night where teammate Tyrese Haliburton tied the Pacers franchise record for assists in a game with 23.