View the original community article here
Last tested: Oct 22, 2018
Write the name of the outer block followed by the nested fields desired in parentheses, like this:
What about from an Sdk?
Example for Ruby scripts:
space(447, :fields => 'id, name, looks(id, title), dashboards(id, title)')
Note that all of the field names are contained in a comma-separated list in a string.