How do export sidecar .xmp's for an entire hierarchy of folders containing photos?

[daveg at justemail.net]

Hi,

I'm moving a collection of Photos to Digikam 5.7.0.

The photos are currently in a nested hierarchy of OS folders.  I've selected the top-level folder as my Album root.

In Digikam, I see & can navigate the tree, and can view images in any specific folder.

I want to export metadata to sidecar .xmp files for all the photos.

I *can* export for any selected group of photos -- but I have to be IN each folder with photos to do that.

How can I export/write sidecar .xmp's for the entire tree/hieraechy at once?