For now the only way to refer another part of the doc (that doesn't belong to the current book) is to use the "static" and full URL.
For example :

 You can find the installation part
[here](http://docs.automotivelinux.org/master/docs/devguides/en/dev/reference/host-configuration/docs/5_Candevstudio.html).

We can think to add a meta tag (eg. %DOC_ROOT% and maybe also %DOC_SECTION_DEVGUIDES%, %DOC_SECTION_GETTING_STARTED%, ...) to make this reference more dynamic.
The above example will become :

 You can find the installation part
[here](%DOC_SECTION_DEVGUIDES%/host-configuration/docs/5_Candevstudio.html).