This sandstone tomb monument is for Konrad von Schaumberg, noted as a court marshall. It’s on the rear wall of the nave of the Marienkapelle, a large chapel plonked down at the center of the market square in Würzburg, where Riemenschneider made his career.
It has a lot of similarity to his other tomb monuments, especially the gravestone of Eberhard von Grumbach in Rimpar.
As you enter the Marienkapelle, look to the back of the nave towards the pipe organ; this work is on the rear wall to the right of the large wooden doors.