What Army or USMC Commissioned Officer position would require getting sniper-qualified?

As far as I know, that's an urban legend as neither the Army nor the Marine Corps would send and officer through the sniper qualification course.

The Marine Corps does have a Sniper Leaders course (SSULC) that trains junior officers/NCOs on the capabilities, limitations, employment, etc. of a sniper platoon, but AFAIK, the Army doesn't have an equivalent course.

I Don’t Think It Would Be Possible,
The 2nd Lieutenants Would Get Lost During Their First Field Training Exercise,

My information is 39 years old, so it may be complete nonsense. I was Marine infantry officer with a secondary MOS as an intel officer. While serving as the Battalion S-2 of a rifle battalion, one of my additional duties was as the Surveillance and Target Acquistion Platoon Leader (Snipers were one of the three sections in the platoon). I received a week of training in field intel school on how to best employ snipers (absolutely no training in how to be a sniper).

I believe, but may be wrong, that the snipers were moved to Regiment sometime after I left the service. But their Platoon leader was still an intel officer.