Comment # 18 on bug 1090193 from Josef Reidinger

OK, in the end two more changes was needed:

https://github.com/yast/yast-installation/pull/754

and

https://github.com/yast/yast-packager/pull/383

I tested it and works for both expanded and non-expanded form.

Just please note that both location of urls have to changed. Online and
extra_url.

My testing to get idea is this control.xml:

ftp://neser-vr.suse.cz/control.xml

and these two rpms as online repos:

ftp://neser-vr.suse.cz/openSUSE_Leap_15.0_Servers.xml

ftp://neser-vr.suse.cz/_openSUSE_Leap_15.0_Default.xml

If one part use expanded url and second use $var variant then in the end both
ended on the system ( I know not a perfect solution, but as it is quite
sensitive part used also by multiproduct DVD of SLE I was more on safe side ).

If something does not work or you have questions, feel free to ask me here or
on IRC.