Create a column from another using the previous/current date in another

[laganlee]

Hi all.

I want to creat a new column using a condition from another column.

If the other column in the same row has a date, then use that date.

Otherwise use the previous date in that column.

Many thanks for looking.

[wdx223_Daniel]

=Table.FillDown(Table.AddColumn(PreviousStepName,"New",each List.Select(Record.List(_),each _ is date){0}?),{"New"})