Create Challenge selector in Leaderboard page.
The user must select a challenge first to be able to view its leaderboard. Extend the leaderboard page with one of selector options:
- Have a new page which contains a list of selectable catalogs. Only if user selects one of them then the leaderboard of models will be shown.
- Have a dropdown menu on top with the list of leaderboards. The first one is always preselected. User can change the menu's value and get selected leaderboard shown.