Adding dynamic data from a MySQL server as layer in ArcGIS Online

I am trying to get my head around ArcGIS Online’s Dashboards.

One thing that I am struggling with, is how to add dynamic data that is served from an external MySQL server in CSV format to a dashboard. While it is easy to add the data to the Map Viewer (via "Add > Add Layer from Web"), it appears as if it is not as easy to add the dynamic data source to a Dashboard.

These expect the data to be present as layer that, if accessed via the web, must either be ArcGIS Server web service, KML, WMS (OGC), WFS (OGC), WMTS (OGC). There is also the option document, which simply imports the data as a table but does not make it available to the Dashboard as layer (e.g. to develop a time-series graph).

is it possible to save data from the Map Viewer as layer to be used in Dashboards? Or is there a way to establish layers from dynamically served CSV data?