It does not work with dynamic zones and (sub)components.
Look at this example:
The compoment “blocks.image-left” looks like this:
Title (Text)
SubTitle (Text)
Body (Rich text)
Image (Media)
Link (Component)
Text (Text)
Hyperlink (Text)
Hint (Text)
In the api result you see that the component “blocks.image-left” only has the id, Title, SubTitle and Body field.