I have a series of headers, level 1-x, and now I discovered I should group them under two headers. Is there a way to "indent" or "push down" the headers so that, for the ones I have selected, level 1 becomes 2, 2 becomes 3 and so on?
And after asking the question, an idea popped into my head, and it worked.
This will push the header with all its sub-headers down one level. Unfortunately it seems I can't select several headers though... but sure quicker than doing it for both top and sub-headers.