just only, no more than
This expression indicates that something is just what it is, emphasizing its limitation or superficiality.
Examples
彼はただの学生に過ぎない。
He is just a student.
これはいい絵ではあるが、名画にすぎない。
This is a nice painting, but it's no masterpiece.
その映画は人気があるが、名作に過ぎない。
That movie is popular, but it's only a good film.
Quick check
彼はただの学生___。