You can access the leaderboards within your Community in the following steps:
1. Click on the Commerce tab on the left side bar.
2. Click on Community.
3. Click on the Community you want to edit.
4. Click on Leaderboard tab
5. You will see those are leading in your leaderboard, their points earned etc.
6. Click on date range and enter the range you want to see the members leading for the date range.
7. Watch the video below for more information.