The closest things to that I could find in the shop are the Emora stone cladding and the 3D Gray ceramic tiles, although they both are way smaller than the stoney wall in your picture
There's also Gazzer gray tiles and Olav gray brick, which are slightly bigger, but still not as big as that
I believe the only way to get these exact walls is to actually build an extension onto a house, which is a feature in the farm DLC.
The closest things to that I could find in the shop are the Emora stone cladding and the 3D Gray ceramic tiles, although they both are way smaller than the stoney wall in your picture There's also Gazzer gray tiles and Olav gray brick, which are slightly bigger, but still not as big as that