Embed query to list children notes

There is a plugin/widget combination already:

• HierarchyNavigate + listChildDocs

In the settings of HierarchyNavigate you can change the page layout to include the listChildDoc widget which will then be inserted automatically.

Perhaps you could check out the plugin linked below, which has four different outlines that can be inserted as blocks, and see if it meets your requirements.
https://github.com/TinkMingKing/siyuan-plugins-index
I'm not a native English speaker, so please forgive me if I misunderstood.

Bro, I think you should definitely take a look at the plugin in the link below, it looks like it does exactly what your screenshot shows it does
https://github.com/TinkMingKing/siyuan-plugins-index

By the way, HistoryNavigate plugin from link above is just something like that (not 1 to 1, but feels ok). So it is possible to fork this and implement, I guess.