// QueryAndChart — prior-quarter total measures
// Paste into Power BI Desktop: Modeling > New measure, one measure at a time.
// Tables: Sales (Month, Category, Units, Revenue), Calendar (Date).
// Relationship: Calendar[Date] (one) to Sales[Month] (many), single direction.
Total Sales = SUM ( Sales[Revenue] )

Sales PQ =
CALCULATE (
    [Total Sales],
    DATEADD (
        Calendar[Date],
        -1,
        QUARTER
    )
)

Change vs PQ = [Total Sales] - [Sales PQ]

PQ % Change =
DIVIDE (
    [Total Sales] - [Sales PQ],
    [Sales PQ]
)