How to sort both the content inside the group and the whole data in SSRS

How to sort both the content inside the group and the whole data in SSRS

How to group the list in the page in SSRS. I have
person_last_name,person_first_name,person_id,email_addres in my table. I
need to do sort the list in the SSRS report.
In my report I have grouped with person_last_name and to sort the data I
have used the sort property in the tablix properties. The data on the
whole is sorted when I selected "Details" option. Then I tried to sort the
content inside the grouped item that was also successful. How can I sort
both the content inside the group and the whole data.