There may be other options for some of these but these should work. Check in the help fiels for more info:
If {?Trial} = "Today" then
{Order.CreateDateTime}= currentdate
else if {?Trial} = "Yesterday" then
{Order.CreateDateTime}=datedd('d',-1,currentdate)
else if {?Trial} = "This Week" then
{Order.CreateDateTime} > dateadd('d',-weekday(currentdate),currentdate)
else if {?Trial} = "Last week" then
{Order.CreateDateTime} in lastfullweek
else if {?Trial} ="This Month" then
{Order.CreateDateTime} in monthtodate
else if {?Trial} ="Last Month" then
{Order.CreateDateTime} in lastfullmonth