In multi-group tournaments, players are assigned to groups based on their ratings, starting with the highest rated and moving down to the lowest.
For example, in a 25-player tournament with 5 groups of 5 players each:
The highest-rated player is placed in Group 1.
The second-highest player is placed in Group 2, the third in Group 3, and so on.
After the first round, the process reverses. For instance, Group 5 gets the 5th and 6th highest players, Group 4 gets the 7th, Group 3 gets the 8th, etc.