You get this pin by having a certain amount of Tier 5 friends in your friends list. The amount of Tier 5 friends counts from the launch of the pins in June/July 2021. Previous T5 friends are not taken into account.
This is the amount you need:
|Level||Tier 5 friends|
After reaching the 5th level, you can level this pin again with the same number. After that, the color no longer changes, but a number appears on the pin. This shows other users how many times you have reached the last level.