Caveat it's been a while since I was on Facebook.
Bottom left on many pages is a clickable link showing your current language setting. It will say something like "Malayu" or "Bahasa Indonesia". Click on it to show all available languages.
Failing that, there's definitely a link at the bottom of the settings page. So, click the triangle top right: in the drop-down list, third item down is probably something like "pengaturan" (settings). On the next page, go to the bottom and look for the Facebook copyright line. Under that, is a link indicating your current language setting: click on that, and all available languages will be displayed.