As of now, there is no option to search in UDW using Solr to find translated Content. Content can only be found in the default language.

Steps to reproduce:

1. Clean installation of eZ Platform v2.5
2. Integrate Solr
3. Create language "French" with language code "fre-FR"
4. Translate "Home" LP to "Maison" in French
5. Search for "Maison" in UDW

Result:
Nothing has been found.

Expected result:
"Maison" LP Content has been found.