Your Team Member Discussions can be filtered for a few different reasons. One is to narrow down the list by criteria to find specific records. Another is to give you a count of all discussions, based on your selected criteria.
You can filter team member discussions by who the discussion was started by, a date range or a category.  
As an example, if you wanted to see how many discussions were started by a certain team member, you would choose the member from the Discussion Started By drop down list, then select the "Filter Discussions" button. You can see the total discussions records label above the list has changed and gives you a total count of all discussion that were initiated by that team member. The list has also changed, displaying only the discussions initiated by the team member selected.
To get started, select My Organization > Team Member Discussions - from the main menu on the left side of the screen.
To filter Team Member Discussions, click the "Filter Discussions" button.
The filter list panel will open above the team member discussions.
Choose criteria to filter the list. Use as many of the filters as you need, you can choose one or many items depending on how you would like to narrow your results.
Click the "Filter List" button and the list will display only the discussions that meet the selected criteria.