何の関係が

what does ... have to do with it?

→ 何
phrase Rare #22,198
what does ... have to do with it? Usually followed by ある or あるの, as in 何の関係がある?. Often used rhetorically to question the relevance or connection between two things.
JA: それが私たちの計画と何の関係があるの?
EN: What does that have to do with our plan?

だけどそれと君の勉強に何の関係が

But what does that have to do with your studies?

— パラサイト 半地下の家族 (2019)

でも彼と野球何の関係が

But what does he have to do with baseball?

— フィールド・オブ・ドリームス (1989)

あなたの隣人同じ学校ニコ何の関係が

What’s your relationship with Nico, your neighbor and schoolmate?

— 嵐の中で (2018)

親父の二の舞になるお父様何の関係が

What does Father have to do with me ending up just like my old man?

— フィールド・オブ・ドリームス (1989)

それと今回の件何の関係があるんですか

And what does that have to do with what happened this time?

— 万引き家族 (2018)