In the define sections window, in the outline list on the left, only "Section #"s can be sorted by a field, ascending or descending. If you want to sort by a primary, then secondary field, make Section 1 sort by the primary field, then make Section 2 (you might have to create a new section) sort by the secondary field. Then put all of your field boxes within Section 2 or in the Detail section and both sorts will apply.
....however, you might get the undesired effect (with dates especially) that if you have 3 different contacts all with the same date in a certain date field, if you sort by that date, the "repeats" will not show on the report, because it's trying to group matching entries together. [Like if you had 7 customers all with one of two sales reps, you can format the report to group the customers beneath their respective sales rep. So it looks like a "header" of the sales rep name with only their customers listed beneath it.]
^The eliminating repeat dates is the problem I'm currently trying to solve.
