The transport package for the current release of siblingNav is broken as of today's date. Anyone have any ideas how to get round it not being able to be installed or an alternative?
You should be able to use pdoNeighbors, I know you can install pdoTools which package includes a number of useful "listing" snippets. The docs are only in Russian, but Google Translate gives a fairly good idea of what it's all about. http://docs.modx.pro/components/pdotools/snippets/pdoneighbors