mluvit každý o něčem jiném, jeden mluví o voze a druhý o koze
One way out of such unhelpful cross-purpose communications is for workplace counsellors to make clear what aspect they are going to start talking about and how other aspects of the topic will be addressed. (Googlebooks)
Otherwise, information in the medical dialogue can be reduced to "two parallel monologues" in which patient and physician are both talking at cross-purposes and in two different languages. (Googlebooks)
I'm not sure that I'm answering your question, or just talking at cross-purposes. (Google)