Use case or problem
Well, I know the obsidian team doesn’t seem to be a big fan of nested metadata information, but there are a lot of obsidian users who do use this (see also Properties: Support multi-level YAML (nested attributes)). My personal use case is an electronic lab notebook vault, that programmatically queries parts of the metadata of ELN notes to include them in other notes, which would not be possible without grouping (nesting) metadata information.
Now, it would be great to use the new bases plugin to create dynamic tables based on this metadata.
Proposed solution
I don’t know how the bases plugin is implemented, but it probably uses some kind of database to store the metadata information. So the easiest way to store the nested keys in the DB and query them would be to store a flattened version of the JSON frontmatter object. Like this the content of each nested key could accessed like any normal non-nested property.
Current workaround (optional)
There is no work around for this problem I would be aware of.