I have a dashboard that I would like to clone and filter several times.
The original has more than 500 rows so I would like to add a filter on one column content.
a. is it possible at the dashboard level?
b is it done through the datasource?
Making sure I understand, you have a dashboard with a table that's got lots of rows in it. You want to clone that dashboard then apply filtering to that dashboard so that only certain rows show up. Is that right?
If that's the case, the answer is, of course, it depends. On table widgets, you can specify the Group(s), Resource(s), and Instance(s) that can be included in the resulting recordset. On any/all of these fields, you can specify "blob" expressions, meaning you can insert a star (*) as a wildcard. If you only wanted certain devices on each of the several dashboards you intend to build, you could create groups containing these devices and use the group as your method of filtering. I recommend putting the group name in a dashboard token (standard name of that token would be 'defaultResourceGroup') and using the token in the widget config. This makes it easier to clone the dashboard because you can modify the token value and clone the dashboard in one single step.
If you want to filter by resource (device), you can specify that resource in the Resource field. If you want to include multiple resources, see the group method above, or select "Add Rows (Resources)" in the widget config and add another resource. If you have only one resource you want to focus on, I recommend setting the device name as a dashboard token (standard token name would be 'defaultResource') and use the token in the widget config. Again, this affords easier cloning.
The same can be done with the Instances field.