Bundle Template

<Bundle name="networkinterfaces" xmlns:py="http://genshi.edgewall.org/">                                                
    <?python          
        bcfg_root = path.split('/Cfg')[0]
        confile_file = os.path.join(bcfg_root, 'etc/networkinterfaces.conf')
    ?>
    <Path name='${config_file}' />
</Bundle>

Cfg Genshi Tempalte

{% python
import os                                                                                                               
                                                                                                                        
bcfg_root = path.split('/Cfg')[0]                                                                                       
config_file = os.path.join(bcfg_root, 'etc/networkinterfaces.conf')
%}
${bcfg_root}

error

Failed to render bundle networkinterfaces.genshi for host vestalac1: "path" not defined