Multiple media sources to template variable

In template variable there is media source section. But you can only have one media source in template variable. Is there a way to add multiple souces in it.

I don't think you can 'out of the box'. (Feel free to prove me wrong).

One work-around might be to create a parent media source e.g. /assets/uploads/
and then create other media sources under that e.g. /assets/uploads/media-source1/ and /assets/uploads/media-source2/

That way you could set the TV to the parent media source and have access to the other ones too.