h5group

// We create a file
a = h5open(TMPDIR + "/test_group.h5", "a");

// We create a set of 10 groups containing 10 subgroups
// Firstly, we create the names
gnames = "Group_" + string(1:10);
sgnames = "SubGroup_" + string(1:10);
names = gnames;
for s=gnames
    names = [names s + "/" + sgnames]
end

// Secondly, we create the groups
h5group(a, names);

// We can check that all is ok
h5ls(a)

// ...and
h5ls(a, "Group_3")

// Free the resources associated to a
h5close(a);