FIRSTNONBLANK Function (DAX)
Returns the first value in the column, column, filtered by the current context, where the expression is not blank.
The column argument can be any of the following:
A reference to any column.
A table with a single column.
A Boolean expression that defines a single-column table .
Constraints on Boolean expressions are described in the topic, CALCULATE Function (DAX).
This function is typically used to return the first value of a column for which the expression is not blank. For example, you could get the last value for which there were sales of a product.
To understand more about how context affects the results of formulas, see Context in DAX Formulas.