A
You can choose which one to show to users either A or B.
B
You can choose which one to show to users whether A or B.
are these grammatically correct if they appear in a document?
if not, How should I write in a document?
A
You can choose which one to show to users either A or B.
B
You can choose which one to show to users whether A or B.
are these grammatically correct if they appear in a document?
if not, How should I write in a document?
Option A is fine; it just needs some punctuation. I'd suggest a dash.
You can choose which one to show users - either A or B.