This achievement is unlocked by winning the stage final tournament. To qualify, your team has to be ranked in the Top 8.
The number of tournaments you need to complete to reach the Top 8 will depend on your performance (aggregate of place + skill points summed up across the last 4 tournaments you've competed in for that stage). If you play on Bronze and win every tournament, it'll likely unlock after the 3rd one.
Once qualified, beat the final tournament on any difficulty to unlock the achievement.