Viz in tooltips got a huge applause when it was launched at the TC a few years ago, but I tell you, I am not applauding the analysts who are now wanting to use this in every dashboard they build.
There is a specific purpose to building dashboards and that is to give your consumers ability to see things at a high level and yes, also have the ability to slice and dice the data using interactivity and filters.
Viz in Tooltip is a great way to get that next level of understanding that goes with the context but is it a good way to do adhoc analysis. That is the issue when my customers are asking for putting dashboards inside of Vizzes. I am not sure about that.
Any how, here is a way I think of using this features
So, this might a decent example of using Viz in Tooltip
But, this is NOT (as it requires too much thought processing from the consumer).
Data Journey 