Comment # 4 on bug 1200029 from Jiri Belka

As noted in a downstream case:

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> Why is there an extra level of nested submenus?

If you meant, why there is submenu 'Xen hypervisor, version
4.14.4_04-150300.3.24' then I can only assume this is because an idea used to
be to have per Xen hypervisor version submenu. (But since I could not install
an older xen package without uninstalling the installed on, this idea seems to
be superfluous.)
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Plus an example:

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menuentry 'SLES 15-SP3, with Xen hypervisor' --class sles --class gnu-linux
--class gnu --class os --class xen $menuentry_id_option
'xen-gnulinux-simple-87ddd18
^^ Xen with latest kernel
submenu 'Advanced options for SLES 15-SP3 (with Xen hypervisor)'
$menuentry_id_option 'gnulinux-advanced-87ddd18d-a4a3-48d6-9e3a-ee49b698a733' {
 submenu 'Xen hypervisor, version 4.14.4_04-150300.3.24' $menuentry_id_option
'xen-hypervisor-4.14.4_04-150300.3.24-87ddd18d-a4a3-48d6-9e3a-ee49b698a733' {
  ^^ latest Xen
  menuentry 'SLES 15-SP3, with Xen 4.14.4_04-150300.3.24 and Linux
5.3.18-150300.59.68-default' --class sles --class gnu-linux --class gnu --class
os --class xe
  menuentry 'SLES 15-SP3, with Xen 4.14.4_04-150300.3.24 and Linux
5.3.18-150300.59.68-default (recovery mode)' --class sles --class gnu-linux
--class gnu --cla
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