Author: Sam Asher
You can clear the cache for embedded Looks and Explores by selecting the Clear cache and refresh option.
For embedded legacy dashboards, however, there is no Clear cache and refresh option:
The workaround is to use the keyboard shortcut (cmd+shift+enter for Mac, or ctrl+shift+enter for PC). See the Keyboard shortcuts in Looker documentation page for a complete list of keyboard shortcuts.
You must click in the iframe or directly on the embedded content in order for the keyboard shortcut to work.
See the New Looker Dashboards Transition Guidelines for more information about transitioning your legacy dashboards to the new dashboard experience.