In Explo, versions follow a linear history. You always start editing off of the most recent version of the dashboard.
Entering Edit Mode
To begin editing the most recent version, click the "Edit" button in the top right of the page.
Dashboard edit controls
In the above example, there is no current draft since Version 3 has already been publish. Thus, when you click Edit, it will create a new draft, Version 4.
Dashboard Edit Interface
Dashboard Editing interface
After clicking edit, the dashboard editing controls will open up. In here, you can create new datasets, add new components, and configure the chart.
All changes that you make to the dashboard elements, layout, and dataset are automatically saved to the current draft
Edits saved to draft
When you refresh the page or come back to your edits later, they will still be there. However, since this is jut a draft, the edits will not be pushed to your production applications until they have been published.