You have to create dimension such a way how you need? an example,
If(DateField=Max(DateField), 'Today', If(DateField>Date(Max(DateField)-7) and DateField<=Max(DateField), 'Last 7 Days' , ......) as Customize field
Best Anil, When applicable please mark the correct/appropriate replies as "solution" (you can mark up to 3 "solutions". Please LIKE threads if the provided solution is helpful