Thor is now on 4 superhero teams in the MCU after Thor: Ragnarok and eventually the Guardians of the Galaxy when they offered. What If...? episode 9 added a fourth team that Thor has been a part of.
Of course, the events in What If...? took place in alternate timelines, meaning that Thor is not the same one that had appeared elsewhere in the MCU. Each episode of the Disney+ series explored a different timeline, culminating in Ultron's acquirement of the infinity stones that allowed him to destroy not only his own universe, but everyone else's as well. Ultron's devastation and limitless power forced the Watcher to put together a team consisting of Evil Doctor Strange, Captain Carter, Black Widow, Star Lord T'Challa, Black Panther Killmonger, Gamora, and Party Thor to stop him.
Every team Thor has ed coaxed something new out of him, allowing for him to embrace different parts of himself at different times and evolve both as a person and as a hero. Here's every superhero group Thor has been a part of in the MCU.
Avengers
The Endgame, Thor's PTSD destroyed much of the humor he possessed, and he was no longer the only powerful alien on the team. The similarities between his skillset and Captain Marvel's necessitated that the Norse god find a new group to . Despite all of Thor's ups and downs, his arrogance about his strength was never unfounded, and he served as a reliable source of information about the wider universe for his Earthly teammates.
Revengers
During Thor's adventures in Ragnarok, he brought together a ragtag team to defeat his evil sister Hela. The Revengers, a name clearly inspired by the Avengers' title, consisted of Thor, Valkyrie, Hulk, and Loki. Thor was much more relaxed in this film than the Avengers ones, providing a lot more of the Ragnarok movie's humor and balancing out Valkyrie's and Hulk's more serious personalities. This team had a very different dynamic from the Avengers' as well since Hulk was the only member from Earth. Yet, Thor was still the most powerful out of the group, even without Mjolnir's help. When Hela destroyed the hammer, Thor went through a lot of personal growth in order to discover just how strong he truly is. Valkyrie, Hulk, and Loki mostly acted as to back up his plans.
Guardians of the Galaxy
Thor was saved by the Guardians of the Galaxy after his first encounter with Thanos in having rather solemn backstories, the Guardians constantly relied on their witty banter to get them out of tough situations, making Thor's more serious demeanor stand out from the rest. His rather regal nature could have put him at odds with the team, but Thor's willingness to go with the flow let him get along rather well with everyone. The God of Thunder eventually even agreed to travel with the Guardians after the events in Endgame, and the team will no doubt appear again in the MCU.
Guardians of the Multiverse
A very different Thor was recruited by the Watcher in What If...? to his Guardians of the Multiverse team to fight Ultron. What If...? episode 7 explored if Thor grew up an only child, which left him a spoiled partier who only cared about having a good time. This backstory made Thor the most relaxed member of the Guardians of the Multiverse in episode 9, during which he bragged that his special skill was attracting unwanted attention. As if to prove the point, a sudden release of incredible lightning power alerted Ultron to their location before they were ready. This Thor never truly seemed afraid, even against the worst odds, and continually blasted lightning at his enemies with limitless confidence. He only wanted to return home to a date with Jane Foster, caring very little about anything else. A bit of a wild card, Thor needed his teammates to keep him in check and focused on the mission.