This cool functionality will enable you to filter the items in a repeated section.
This means that if you are pulling multiple Accounts, for example, you can then filter to show only part of them based on a certain parameter. For instance, you can filter based on the “Account Type” picklist values, so if the filler selects "Customer- Direct" only the accounts that have this value in their Account type will be shown.
Watch how to filter repeated items based on parameter
Enjoy!