How can I show only the most recent record in my dataset versus multiple per client? Example, show only the last sale per customer vs all sales for a time range.

A lot of this will depend on the structure of your data,  but one of the easiest ways to accomplish this is to use a formula function, max(?).

Assuming you have a date field which marks the timestamp of each record,  if you apply the max(?) formula to the date field, it will return only the most recent date for each record in your dataset.