Custom measure for by date (previous year)

[Crystal_Taren1]

Hello Looker Community

I am trying to create a column with a custom measure that references a metric’s total for the previous year.

The metric is broken out by week in the look and when I tried to add a column using a custom measure I get an error that it should be a yes/no or it returns 0’s.

so far I have tried filtering the metric with a date_add( -1, date).

Any help is appreciate thanks!