How to set "target" for Custom Properties?

[sjyong]

Hello, I solved my original question, so this question is edited:

I wonder, how I can work with "targets" in the custom properties operator.
In the attached scene I was trying to use the targets.

(It worked with "self" after some adjusting)

There is the option to "Set" Values as target.
I did not find something detailed in the documentation.

It would be great if someone could explain.
Thanks

Although it is lengthy, you can easily understand it by referring to the video below.

https://youtu.be/hVb-NTCGuvI