This feature is only available when JeppView 3 is installed on the same machine.
The Jeppesen Airway Manual displays information only in English regardless of what language you select on the Text Viewer Toolbar.
The Bottlang Airfield Manual (VFR Text) works somewhat differently because it supports multiple languages. Various categories under the Bottlang Airfield Manual that support different countries (France, Germany, Austria, and so on). Each country listed has information in specified languages; all of them have English.
Austria has the same information in English and German.
Belgium has the same information in English and French.
France has the same information in English and French.
Germany has the same information in English and German.
Switzerland has the same information in English, German and French.
Information for all other countries is in English only.
Depending on what language you select in the toolbar, some countries might not have any topics in that language. For instance, when all languages are selected, you will see all topics available for that country in the languages that it supports.
When you view the France book and change the language mode to French, you see only the topics in French.
When viewing the France book and changing the language mode to German, you will only see the topics in German. In this case, there will be no topics to display.