Custom fields resolution when exporting

When a folder name is dynamically generated with the usage of custome fields, the resolution of the folder name doesn't work when exporting.
Example:

• the folder is named Customer - Rome - 1234, where Rome and 1234 are respectively SITE_CUSTOM_FIELD2 and SITE_CUSTOME_FIELD3
• the export dialague suggest the name Customer - $SITE_CUSTOM_FIELD2$ - $SITE_CUSTOM_FIELD3$.rdm

Please double check this name resolution of folder/sites because the same issue may apply to different contexts like scripts.