I/O from XDMF/HDF5 files in dolfin-x

You can read your mesh with:

import dolfinx
from mpi4py import MPI

with dolfinx.io.XDMFFile(MPI.COMM_WORLD, "idealized_LV_ref_0.xdmf", "r") as xdmf:
    mesh = xdmf.read_mesh(name="mesh", xpath="Xdmf/Domain/Grid")

Reading the scalar values and vector values associated with the nodes requires some more work.
I might not have time to get back to you before I go on holiday, so the earliest I might have a reply for you is end of next week.

If you want to explore this, I would start with: Wrong order of dofs after creating mesh from lists of points and cells - #2 by dokken