You can preset a filter for our Custom Canvas dashboard using dashboardState. It will apply to all users of the dashboard. Note: for non-Custom Canvas dashboards, you can also do this but you’ll need to store their selected variables in your frontend and then pass them back into Embeddable when that user returns.
If you look at the Tokens API, you’ll see we ask for a user key. This is so we can store a dashboardState against each user (e.g. remember which filters have been set).