Scan using 2, 3, and 4 Day Aggregation Periods

"is it possible". Perhaps. Certainly not for free. This would require some very complex code. One of the main issues to address right from the start.

1. How do you decide which days to pair up?
2. If you do a 2 day aggregation period, do you combine Monday and Tuesday? Or Tuesday and Wednesday?
3. How do these days get combined when you select a 2 Day aggregation period on a chart?
4. Does it vary based on the current day of the week or the first day of the week on the chart?

Each week we have an odd number of trading days. You can't evenly combine them to create a 2 day, 3 day or 4 day aggregation period.

It would take enormous amounts of complexity just to compute the basics, Open, High , Low, Close, Volume. Then you would need to build a custom version of any indicator you would want to apply. Many of which would be far too complex to accomplish in a simple scripting language like Thinkorswim.

In summary. Just move to another platform that supports this sort of thing natively.