The current "Manage Dashboard" dialog is functional, however if you have access to a large number of dashboards, it becomes difficult to manage having to slowly scroll through a long list to make sure you don't miss the dashboard you're looking for if you want to add a sub-Dashboard.
I think there are 2 aspects of this dialog that could be separated to provide better functionality.
Adding a Sub-Dashboard/Editing Dashboard Name:
- Search functionality to find the dashboard you're after
- This then filters the list to that dashboard with the same arrows to collapse/expand that dashboard tree
- Either add a sub-Dashboard or edit Dashboard name should then be available
Re-ordering Dasboards/sub-Dashboards:
- Whilst Drag-and-Drop functionality is simple and intuitive for an end-user, when the list of dashboards becomes too long it doesn't work as well; especially inside a smallish pop-up dialog
- As much as I don't like to compliment Microsoft, the method for managing columns in SharePoint list views works quite well by using check-boxes to hide/un-hide and a number drop-down to adjust the position in the ordering.
- Even if the method isn't changed from the drag-and-drop, the dashboard re-ordering should be accessed via a dedicated page within the user's profile settings.
The Manage Dashboards link could be broken into 2 buttons
- "Edit Dashboards": brings up the dialog with search
- "Arrange Dashboards": links directly into the page within the user profile settings