In the sentence "What do you miss the most?" the word "what" is the object of the verb. So it would be easy to think that the correct translation is "Qu'est-ce que te manque le plus?" However, in French the construction differs from English. The French construction is essentially "What is missing to you the most"? Hence "what" has become the subject of the verb and accordingly the correct translation is "Qu'est-ce qui te manque le plus?"
Can someone confirm that this analysis is correct please?