By selecting the name of the language from the Language list in the Search window you change the currently selected set of glossaries to be searched or browsed:
By default, all glossaries of newly integrated languages are selected. You may choose to limit your search and browse operations by selected glossaries. Select or clear the checkboxes on the left of the glossary names to compile a specific set of glossaries you are interested in.
The All button automatically selects all available glossaries.
The None button automatically clears any selection.
See also:
Entering Term and Setting Search Options