Several different matchups have good cases.

Celtics vs. Heat:

Played each other in 2020 playoffs (Heat won), 2022 (Celtics won), 2023 (Heat won)

Celtics vs. Bucks:

Played each other in 2018 playoffs (Celtics won), 2019 (bucks won), 2022 (Celtics won)

Celtics vs. 76ers:

Played each other in 2018 playoffs (Cs won), 2020 (Cs won), 2023 (Cs won)

76ers vs. Heat:

Played each other in 2018 playoffs (76ers won), 2022 (Heat won)

Heat vs. Bucks:

Played each other in 2020 playoffs (Heat won), 2021 (Bucks won), 2023 (Heat won)