The advanced segment setting of Data Trend allows you to dictate how the last 3 data points for this criteria have been trending for a user before they match, either 'Upward', 'Flat', or 'Downward'.
For example;
You may want to match users who are currently in the Struggling state with a discount code.
However, if a user is trending positively, and recovering from their Struggling state, you may not wish to include them in the experience.
By only including users whose 'Data Trend' is 'Flat' or 'Downward', you have further control on who would be targeted with the experience.
Take a look at the video below to learn more;