Is there a way to get every second, third, or fourth of a data

So I have a list of data that is appearing on my web app. This data gets displayed to a chart. I would like to have this chart display the last 7 days, 30 days, and a year. But for example with the 30 days, I dont want it to show every single day. I would rather it show every other 3 days. Is there a way to “Do a search for” or sort my list so that I can show every other 3 days?

What kind of data is it? Numbers or objects?

If it’s numbers, :GROUP could probably help you with that

EDIT: if you need to really get one every 3 object in a list, I think you’ll need to have an incremental unique number on the list of objects.