DOC: added release note, this fixes #8173

Author: mortada

doc/source/v0.15.0.txt

@@ -441,8 +441,14 @@ Enhancements
 - ``pandas.tseries.holiday`` has added support for additional holidays and ways to observe holidays (:issue:`7070`)
 - ``pandas.tseries.holiday.Holiday`` now supports a list of offsets in Python3 (:issue:`7070`)
 - ``pandas.tseries.holiday.Holiday`` now supports a days_of_week parameter (:issue:`7070`)
+- ``GroupBy.nth()`` now supports selecting multiple nth values (:issue:`7910`)
 
+  .. ipython:: python
 
+    business_dates = date_range(start='4/1/2014', end='6/30/2014', freq='B')
+    df = DataFrame(1, index=business_dates, columns=['a', 'b'])
+    # get the first, 4th, and last date index for each month
+    df.groupby((df.index.year, df.index.month)).nth([0, 3, -1])
 
 - ``Period`` and ``PeriodIndex`` supports addition/subtraction with ``timedelta``-likes (:issue:`7966`)