Can I choose a language for the translate filter? So I've built a language switcher as per this answer.

I want the text for each link to be in the native language, for example I want the link to the English locale to say "Read this page in English" and the link to Spanish locale to say "Leer esta página en Español" etc.

However using the |t filter uses the locale that you're currently on, so if I'm on Spanish it says "Leer esta página en English".

Is there a way to pass in a parameter or something to say, for example, |t(Spanish).

Thanks!
Yes. You can see all of the arguments the |t filter supports by looking at the docs for Craft::t(), the function that |t maps to. Its $language argument defines the target language translation to use. So in your case you could do this:

{{ "Leer esta página en Español"|t(language="es") }}