Only the first location is displayed when using f_space_facet

When specifying several f_space_facet parameters, like in

http://localhost:8080/xwiki/bin/view/Main/Search?sort=score&sortOrder=desc&highlight=true&facet=true&r=1&f_space_facet=0%2FTestSpace.&f_space_facet=0%2FTestSpace2.&f_type=DOCUMENT&text=Test

only one location is shown, the first that is given:

The results correctly include all the locations though.