Thank you, I have now referred to the custom state in the data source .
Despite setting the default value to ‘1’ I still see ALL groups.
I see what I was doing wrong, the button was not referring to the index page custom state so it was asking me to create a new one. I have now added the workflow to the button (below) but of course nothing works because the RG is always displaying ALL groups.
Another side issue, I am also trying to add a custom state so that a button will show events happening ‘today’. You gave me advice to add a custom state to achieve this in this post but I can’t figure out how to add 2 states to the RG data source (it just won’t let me). I’ll update the thread above to keep issues separate.