How to create a Wave dashboard list filter?

Question

I want to use a Wave dashboard in a page layout, and I want to pass a parameter to the dashboard, to use as a filter. The documentation states "To filter by a dimension, be sure to create a list widget in the dashboard for the dimension."

So I go to my dashboard, I click on List. A List widget appears, but then what? I do not see how I can modify the list or add anything to it. The documentation doesn't tell how to do this.

I recently discovered the expert editor (Ctrl+E) for dashboards. I clicked a couple of times on the List icon, and moved the List widgets around. I clicked Save. I typed Ctrl-E but I can't find the List widgets in the JSON source. I return to the normal editor and the List widgets no longer exist. User friendly and intuitive are not the phrases that spring to mind.

Answer 1

So, after a lot of Googling, I came upon the following. First, open the dashboard. Then create a lens that does a GROUP BY for the relevant dimension. Clip it to Designer. Go to the dashboard, click on the List widget to create an empty one and then click on the clipped Lens to fill the List. Now the List is persistent, i.e. it also exists in the JSON file.