YOU SAID:

I wish I had a fish in a fish in a fish

INTO JAPANESE

魚の魚に魚がいたらいいのに

BACK INTO ENGLISH

I wish there was a fish in the fish fish.

INTO JAPANESE

魚の魚が魚にあればいいのになあ。

BACK INTO ENGLISH

I wish the fish were fish.

INTO JAPANESE

魚が魚だったらいいのになあ。

BACK INTO ENGLISH

I wish the fish were fish.