RANK.EQ Returns the ranking of a number in a list of numbers.
Syntax
RANK.EQ(value, columnName[, order])
Parameters
value – Any DAX expression that returns a single scalar value whose rank is to be found. The expression is to be evaluated exactly once, before the function is evaluated, and it’s value passed to the argument list.
columnName – The name of an existing column against which ranks will be determined. It cannot be an expression or a column created using these functions: ADDCOLUMNS, ROW or SUMMARIZE.
order – (Optional) A value that specifies how to rank number, low to high or high to low:
0 FALSE – Ranks in descending order of columnName. If value is equal to the highest number in columnName then RANK.EQ is 1.
1 TRUE – Ranks in ascending order of columnName. If value is equal to the lowest number in columnName then RANK.EQ is 1.
Return Value
A number indicating the rank of value among the numbers in columnName.
Reference Data
https://docs.microsoft.com/en-us/dax/dax-function-reference