A quick method would be to :-
- Export the visualizations from management -> Saved Objects,
- Edit their IDs (_id) in the JSON obtained and then import those visualizations.
- Same way, export the dashboard and match the new IDs in "panelsJSON", (You can just append '-clone' at the end of every _id in visualizations and dashboards) and that should work like a charm upon importing.
This way you have just cloned all your visualizations and the dashboard.
See, Kibana stores all it's data in Elasticsearch under '.kibana' index. The Visualizations are under 'visualization' type and then we have :- dashboard, url, index-pattern, etc. And these Objects can reference each other, like Dashboards will be referencing the IDs of their visualizations and visualizations will be referencing their searches, etc. So if you clone a dashboard, only dashboard Object is cloned as it is, it's references remains the same.