it's a matter of
Mi abuelo murió en la trinchera y es una cuestión personal.
My grandfather died in the trenches, and it is a personal matter.
— Taxi Express (1998)
Es una cuestión discutible, quién trajo a quién.
It's a debatable question who brought whom.
— Moscú no cree en las lágrimas (1980)
Es una cuestión de no sé, no es una cuestión material.
It's a matter of, I don't know, it's not a material issue.
— Divorcio a la italiana (1961)
This is a moral issue.
Un uso excesivo de Internet no es una cuestión médica o psiquiátrica.
Excessive internet use is not a medical or psychiatric issue.
That's a private matter.
It's a complicated matter.