Saving boundary data of PART of the boundary

Dear all,

For an application I want to compute the wall shear stress for complex geometries.
These complex geometries have an inlet, 5 outlets and a wall with no-slip condition.
At the wall I am computing the wall shear stress, and I save this to an xdmf file.

However, the wall actually consists of 4 separate areas (with different markers in the mesh), and I would like to write an xdmf file for each of those areas, so I can distinguish between their wall shear stress values in post-processing.

What would be the best way to accomplish this?
With kind regards,

How about using a MeshView as explained in https://dl.acm.org/doi/abs/10.1145/3471138

Thank you so much, this is exactly what I was looking for.
I will attempt to implement this for my case. Have a nice day!