I'll take this.
In the attached, I floated everything that was previously tiled. I like to float everything. It gives me more control, and as you'll see later, I hide things behind other things, and you can't do that with tiled dashboards.
So Dashboard 1 is the original dashboard with a lot of things floating. and you'll notice that the Region legend for two of the sheets are floating separate from each other. (Swap between Bar Chart and Time Series to see them activate.)
Go to Dashboard 2. Change the selector to Time Series. You will see that I have added a container, and I created a sheet called "Pop out Time Legend". (Check out the sheet. I use the same selector method to control whether or not this sheet displays.) Swap the parameter to Bar chart. The Time Series legend moves as the pop-out sheet disappears. This is the trick to getting other objects to swap in and out!
Go to Dashboard 3. While "Time Series" was selected, I positioned that container so that the legend displays just to the right of the container that has all the swapped sheets. Once I liked its position, I changed the floating order of the pop-out container to the bottom of the floating order list. Now that pop-out sheet does its work behind the sheet-swapping container, and the user doesn't see anything except the legend when it gets pushed into view. Swap the parameter again between bar chart and time series to see the time series legend pop in and out.
Go to Dashboard 4. I did the same series of steps for Bar Chart. It has a dedicated pop-out sheet (change the filter value so that it activates for bar chart!.) And I positioned the floating coordinates exactly the same as the time series container. Now one or the other will display as appropriate. If there are a dozen such legends, just do a dozen of these containers and pop-out sheets and pile them all on the same real estate -- BEHIND the swapping container.
We made a video that demonstrates this.. You can find it here:
Some day I'll make a better one, but for now it gets the concept across.
vizselect A.twbx 337.0 KB