The regular expression options, -f and -rf, provide you with considerable flexibility for specifying which parts of the fabric registry to export. For example, to export every version of the default profile's data, you could use a command like the following:

fabric:export -f /fabric/configs/versions/[0-9\\.]*/profiles/default/.*

Where the double-backslash, \\, is required to escape the period, ., so that the period character gets interpreted as a character literal.