I was surprised there isn't actually a TODAY option for a segment leaderboard on the web. That exists only in the app but not on the web. TODAY option is very useful when comparing my performance to others after a race. I like to look at all segments along the race course and see how I did. When using the TODAY filter, that would include mostly only people who participated in the same race.

Additional to filter=overall I know:

• filter=current_year
• filter=overall&gender=M
• filter=overall&gender=F
• filter=following
• filter=my_results
• filter=age_group
• filter=weight_class
• filter=club&club_id=123456

@Silentvoyager There is one, but not directly accessable with an URL

Follow up question, is it possible to apply a specific filter by month to a segment?

Thank you all for comments and information.  I'm concluding that a comprehensive list of /segment/ filters is not available in Strava Community.  Does anyone know of a app or API that can be used to score a KOM based on Strava segment data?

@Silentvoyager - there is a "Today" option on the web.  You can't see it from the segment view within the activity, you have to open the segment detail page itself.  From the dropdown, you have the options for "all time", "today", "this week", and "this month".  If you click on one of those, you will also get an option for "this year".