You can put a dashboard at the top of your My Data page by making it a favorite.  Here are two ways to do that.

Option 1: On the My Data Page

To create a Favorite, simply click on the heart next to the dashboard you want to favorite.  When you refresh the page it will be in the Favorites category.

To remove a dashboard from the Favorites category, simply click on the yellow heart next to the dashboard name.  When you refresh the page it will be removed from the category.

Option 2: When Looking at a Dashboard

You can also add a dashboard to the Favorites category while looking at the dashboard. Simply click "Add to Favorites" at the bottom of the left side bar.

To remove the dashboard from the Favorites category from this view, click on the "Remove from Favorites" in the same place.