If you would like to export your dashboard, you may first display the print area on your workspace. This will enable you to arrange your elements in a way such that they won't be cut off when you generate an export.
This display option is available in the sidebar: simply go to the sidebar, click on the third tab to expand the "Zones" tab, then tick the box to enable display of the print area (export limit). Next, select your desired format (portrait or landscape).
This action must be taken for each and every tab of the dashboard you wish to export.