NetCDF coordinates in parent group is not used when reading sub group

Code Sample, a copy-pastable example if possible

ncfile_cf = "x07z00017_cf.nc"
with xr.open_dataset(ncfile_cf, group="x07") as ds:
    ds_data_cf = ds.copy(deep=True)
print(ds_data_cf)
     
<xarray.Dataset>
Dimensions:  (time1: 100000, time2: 2)
Dimensions without coordinates: time1, time2
Data variables:
    aps      (time1) float64 ...
    iact     (time1) float64 ...
    vact     (time1) float64 ...
    dps      (time1) float64 ...
    tss      (time2) float64 ...

Problem description

When reading a sub group from a netCDF file with dimensions defined in the root group, the dimensions are not read from the root group. This contradicts the netCDF documentation, which states that dimensions are scoped such that they can be seen by all sub groups.

The attached netCDF file demonstrates this issue.
x07z00017_cf.nc.zip

Expected Output

The dimensions from the root group should be used when reading the sub-group.

with xr.open_dataset(ncfile_cf) as ds:
     for coord in ds.coords:
         ds_data_cf.coords[coord] = ds[coord]
print(ds_data_cf)

<xarray.Dataset>
Dimensions:  (time1: 100000, time2: 2)
Coordinates:
  * time1    (time1) float64 0.0 1e-06 2e-06 3e-06 4e-06 5e-06 6e-06 7e-06 ...
  * time2    (time2) float64 0.0 0.1
Data variables:
    aps      (time1) float64 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 1.0 1.0 ...
    iact     (time1) float64 -0.00125 -0.000625 -0.00125 -0.0009375 ...
    vact     (time1) float64 -0.009375 -0.009375 -0.01875 -0.01875 -0.009375 ...
    dps      (time1) float64 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ...
    tss      (time2) float64 0.0 0.0

Output of xr.show_versions()

Start with the xr.open_dataset call using the attached NetCDF file and the group="x07" argument. Trace how dimensions and coordinates are loaded for a sub-group, then compare that behavior with loading the root group. Done means root-group coordinates are available when opening the sub-group, matching the expected output shown in the issue.