To go from 0 to 1 (win the base badge), you need to be among the top 10 tier 0. This is just as it always was.
To go from 1 to 2, you need to be among the top 8 who are tier 1 or less.
To go from 2 to 3, you need to be among the top 7 who are tier 2 or less.
To go from 3 to 4, you need to be among the top 6 who are tier 3 or less.
To go from 4 to 5, you need to be among the top 5 who are tier 4 or less.
To go from 5 to 6, you need to be among the top 4 who are tier 5 or less.
To go from 6 to 7, you need to be among the top 3 who are tier 6 or less.
The "or less" DOES NOT appear on the "badge page", consequently players might be confused about Martha.