Welcome to the forum!
So for the result, you want to have a black circle with white on the inside, but without the black dot? If I understand correctly, then this is what I would do.
Right after you click Break Apart, and while everything is still selected:
-- hold the Shift key
-- click once on the dot (this deselects the dot, and leaves the other paths still selected
-- Path menu > Combine (this puts those other paths "back together")
Now you should have the black circle with white inside. And the dot is separate and you can move it around, or whatever.
Thank you very much for your quick reply.
O~K, in a first few tries, I couldn't do what you had told me.
And I figured it out why I couldn't, that's because I was Breaking apart it while I was in the node tool mode (after pressing F2).
Breaking apart an object in the node tool mode and in the object mode (mode appears after pressing F1) is different, isn't it?
After figuring out that, I could do exactly what you had told me.
Breaking apart everything and putting together everything other than what you want to be broken sounds a bit going around the bush, but maybe that's the most effective way now.
You have helped me! solved.
Thank you very much.