This feature checks every 'X' minute for changes in your Jira issues, or if someone has recently changed the ScriptRunner add-on settings. If changes have occurred, then filters are synced with the changes made to the issues in your Jira instance. Filters are always run with the same set of permissions as the user who created the filter.
You can select the Filter Sync Interval Period from the options available in the drop down list to specify how often ScriptRunner synchronizes your filters. The maximum interval period allowed is one hour, however, the default interval of five minutes is recommended.
You should adjust the default interval period if you notice that filter synchronizing makes too many requests to your Jira instance and causes a performance problem.