There’s a bit of info in: 
Though I’m hoping to leave a template somewhere that people can copy&paste, and then fill their own links in.
I don’t get into all the details of the nesting, but you just put another details/summary block inside the first one (and so on, like the matryoska Russian dolls). You can nest Hide Details using the 
method too, but the Summary won’t be as amendable.
And you can still use the 
method to put your toys in the main body (so you only need to use the href version in the summary section).