Unless you export the data outside Splunk, anyone can clone a Dashboard (perhaps only to their own private view, but clone it nonetheless)
If they’re not supposed to have access to various data sources, you need to restrict their access to those sourcetype(s) or index(es)
from User warren – Stack Overflow https://stackoverflow.com/questions/74100354/splunk-is-there-a-way-to-remove-the-clone-dashboard-option/74102038#74102038
via IFTTT