When you check the results for an advanced filter that you’ve applied vs the results for a smart group set with the same filter, differences are expected.
Moreover, the date selected in the calendar also has an impact, accordingly:
the filter shows the results taking into account the selected time frame; however, filters on Sessions, Bounce rate, Conversions, Conversion Rate, Revenue, Rank Change or Rank Change (Absolute) shows results for the last 30 days (they do come with a warning for this, as in the below example).
the saved filter that’s now a smart group would only refer to the last 30 days; this applies to the time-relative criteria: Rank, Rank Change, Rank Change (absolute), Warnings (like Cannibalization)
Let's take the “Rank equals” rule as an example:
in the filter case, it would show the results for the last day in the selected time frame,
while in the smart group with the same rule, it would be the results for the last available rank.
If it’s still unclear or if you have any related questions, feel free to get in touch with us via the in-app chat or email.