Change second tabset on click in flexdashboard

[mfherman]

I'm working on a self-contained flexdashboard project and I'm wondering if it's possible when a user clicks to a new tab in one tabset, it changes to a new tab on a second tabset as well.

So for example, when you click on "Chart B1" below, I would also like to change view to "Chart B2" in the second column. And clicking on "Chart A2" would change back to "Chart A1", etc. etc.

---
title: "Untitled"
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
---

```{r setup, include=FALSE}
library(flexdashboard)
```

Column {.tabset}
-----------------------------------------------------------------------

### Chart A1

### Chart B1

Column {.tabset}
-----------------------------------------------------------------------

### Chart A2

### Chart B2

EDIT: Now also asked on StackOverflow and GitHub.

[mfherman]

And now answered on SO!

Change second tabset on click in flexdashboard