There is no feature to have queries grouping by other than the raw attribute in Web Desk.
You cannot have a range of the Creation Date like you can in console.
However, this can still be achieved with some design changes and use of a Calculation.
If you create a string(100char) Attribute on the Incident Object and create a 'Before Read' Calculation to show the Week and Year you can then set your Query to Group by this attribute instead of the Creation Date and with this get the weekly grouping that you want.
If you have already existing Incidents that you want included in this, you will need to create the Calculation, make sure that it's working and then run a scheduled calculation to set the value on all OPEN Incidents.
(Please note that you will not be able to run the scheduled calculation on any Closed Incidents)
The Calculation that you would need to use would be as follows:
static def GetAttributeValue(Process):
Cal = System.Globalization.GregorianCalendar()
Date = Process.CreationDate
Week = Cal.GetWeekOfYear(Date, System.Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Monday)
Value = String.Format(" Week ", Date.Year, Week)
You will need to set a dependency on "Creation Date".