Expanding group selection in the sidebar

I am not sure what it is called, but I think it does exist. Is there a way after drilling down to a folder in the main window, to spring open that drill-down in the sidebar? I seem to think there is a shortcut, but cannot find anything on the modifier keys. I do not have Automatically expand & collapse enabled as I find this is mostly more of an annoyance than a help.

Also, as an aside:

I’ve got Double-click opens group in a new window unchecked and I’ve got Double-click opens document externally unchecked.

I notice if I use alt-double-click on a group I can override the preference and open a group in a new window. But there is no similar override for opening a document in an external app. The alt-double-click feature would be a neat addition.

Thanks in advance for any help.

There is no hotkey for spring-loaded groups. If you hover a drag over a group it should expand after a pause.

It’s more… I’ve navigated down a group structure in the main window, and I realise I want to open that structure in the sidebar to keep it while I’m working. Kind of when I search, I can use the Reveal command to open the actual structure of groups where the item lives in the main window. Is there a way to then transfer this into the sidebar?