[TYPO3-Solr] Adding a cObj as facet fails

[Axel Jindra]

Hi,

I want to add a facet and have tried several ways to get the 
additionalField indexed. But the facet list only shows the string, not 
the cObj.
This is my setup:

plugin.tx_solr.index.additionalFields.subdomain_s = TEXT
plugin.tx_solr.index.additionalFields.subdomain_s {
   data = levelfield : 0, subtitle//title
}
plugin.tx_solr.search.faceting.facets.subdomain {
   label = Teilauftritt
   field = subdomain_s
}

In the facets only "TEXT" is displayed. I have tried other cObject types 
like HTML but there was no change. What am I doing wrong?

Thx,
Axel.