There are 2 languages in PowerBI - M and DAX. M is for data loading and DAX is for further data transformation.

You can use these formulas in M to get the Quarter of the Year.

// Current Quarter of the Year
Number.ToText(Date.QuarterOfYear(DateTime.LocalNow()))
// Previous Quarter of the Year
Number.ToText(Date.QuarterOfYear(Date.AddMonths(DateTime.LocalNow(), -3)))

In DAX it's even easier to get the quarter of the current Year.

CurrenntQuarter = QUARTER(NOW())

Use PowerBI and enjoy 🙂