Hello!
I think it would be great if we could apply more than just 1 level of grouping to a table/list but more importantly support to group by formulas and date fields would be really useful!
For example I am tracking time spent on projects and it would be great to group the time entries by the month and see the total time spent each month.
And to use the same example for the multiple levels of grouping, I could group by year, month, week to get even more granular summaries on the timesheets.
Of course I assume this information could be obtained via reports/charts but I am on the free plan at the moment and I imagine there would be a lot of use cases for these features.