The filters available will depend on the report you are viewing and will appear in the top half of the page. Depending on the rules of the filter you simply enter data to be searched or select from the options, then click on the Run Report button to apply the filters and view the refined results.
The below image shows the filters available for the Activity Status Completion Report which is one of the standard default reports set up on the Unicorn LMS.
For example, if you only want to view the users who haven't completed a specific activity, you can type the name of the activity in the Activity Name field and select Incomplete and Not Attempted from the Completion Status drop-down menu then click Run Report.
For further information about using report filters, please see the Editing Report Filters guide.
Now that you have applied your filters, you may be ready to Export the Results of your Report.