If the POV does not know it, you would want to keep it untranslated. But if the POV does know it, you should translate it. This would give an audience experience roughly like the character herself, based on her understanding of what is being said. That is, unless what is being said is vital to the plot, for example
"Bob Thlaka Kar" if important, translate it but say something akin to, "'Bob is the Hero', she said in Sarit", and make sure to emphasize that what is being said is not understood by the POV Character.
But to speak more objectively, you do it however you want. As long as the point is gotten across and doesn't bring about confusion as to what the intention is.
Look at Stormlight Archive for example, where there are many different languages, and characters can, at times, go back to their own language. Like Lumanor, for instance, whose native language is Unkalaki, so he at times say some Unkalaki words, either out of exclamations of suprise, or to describe more foreign concepts. And they are not translated due to Kaladin not knowing Unkalaki.
Such as when he was shocked at something, not going to spoil what, he said "Umalakai'ki! Kama mohoray namavau—", which was not understood by Kaladin. Or when with more religious or cultural phrases he would speak in his own tongue, "Uma'ami tukuma mafah'liki...".
Also, some terms are just kept in the native tongue even if understood, due to them being very specific or culturally important, like ''Lait'', which is not translated, and refers to a geographical formation which protects from the winds of the Highstorms.
In general, it does language very well, and would be a point of inspiration for how to implement it, in my opinion.
But that is just a suggestion.