It may as simple as creating the dashboard from Splunk Web UI of any search head or deploying the dashboard from the deployer (in case it's part of the app that's managed via deployer and you want to keep this dashboard read-only.
Great - I like the simple way of creating the dashboard from Splunk Web UI of any search head ; - )
Assuming that prod and stage are separate systems your best bet might be to export the relevant app from stage and install/upgrade the version on prod.
If your on a recent version you can use the
splunk package app command.
@somesoni2's solution will work a charm if all of the relevent knowledge objects are on the Prod system, but if the new dashboards have dependancies on eventtypes, fields, tags etc you might find that some of the panels may not render.
Try @somesoni2's idea first as its definatly the simplest, but if you find that the dashboards dont render you may need to move the whole app (or copy the conf files by hand)