No need for any global field, let alone a repeating one.
Let's say your table of search criteria used by your Marketing Director is called "Targets" and has the following fields defined in it:
TargetDate, StartDate, EndDate, Region //add as many fields as needed here
Your Script can run like this:
#find most recent TargetRecord not dated for the future.
Go To Layout [Targets]
enter find mode 
Set Field [Targets::TargetDate ; "<" & get ( CurrentDate ) ]
Set Error Capture [on]
IF [ Get ( FoundCount ) > 0 ]
#Find records to match target criteria
Sort [No dialog ; restore ] // sort by target date in descending order
go To Record/Request/Page [first]
Set Variable [$DateRange ; value: Target::StartDate & "..." & Target::EndDate ]
Set Variable [$Region ; value: Target::Region ]
Go To Layout [Clients]
Enter Find Mode 
Set Field [Clients::Date ; $DateRange]
Set Field [Clients::Region ; $Region]
That's just a basic outline. Much more sophisticated finds can be performed using this basic technique.