I may or may not completely understand your question but I'm taking a shot anyway....
I think you'll need at least two dashboards to maintain. If you are connecting to a DB then this process gets a little easier after the dashboard is build as Tableau server can just update the connected source's extract. Flat files (excel, csv), these will be a bit more of a hassle. In any approach
I've created my user filter option using an example from Tableau (Example - Setting User Filters) and I was able to get it to work as I would expect with only minor issues on the dashboards. Using the user filter approach to design takes a unique approach to maintain a visually complete dashboard. You run the risk of pot holing (my term) your dashboard depending on user - meaning areas of your dashboard are just blank boxes. I gave one user access to Costs by Region and limited them to only East. But my dashboard had a selector for Region so when they select any other region than East, all my sheets go blank or views that didn't have Region tied to them still show. It looks like a skeleton dashboard frame. Not exactly a clear indication you don't have permission to see that data and prompts more questions.
This is where two dashboards address the issue; Admin and Limited User. This is because you want to include a filter for "Region" on the Admin dashboard so they can drill in. The limited users only see their specific region so they do not need this filter at all.
Hope this helps.
Thanks very much for this reply, which actually was helpful. However, the issue that we basically had (we now know) was that the account was set up wrong, so that the online data could not read the filters I had set up. We are now getting somewhere with this.
However, we do want to have a look at the API.
So lots in what you said to think about, and thanks for taking the time.
Glad to hear it was easier than we thought . I haven't done much with the API approach but I'm also looking into utilizing this approach as well.
Glad to help.