How do I do that if I'm using up to level 7 for headings

You use levels 8 and 9.
You can have the text look how you want.

Each level must be attached to a unique paragraph style. Those styles do not have to look any different. The indents can be the same for both of them and you need not have indents at all.


=====================================

I am seeing 4 levels in what you posted, but you may be using other levels for something else. That you want your seventh section numbered 7 does not mean you are using seven levels. That number is your first level. The 5 in 7.5 is at the second level. The 1 in 7.5.1 is the third level.