Adding a clickable button. If clicked, it should change the survey flow .

Did I put my question in a wrong thread?

There are several threads on the forum related to end survey buttons. Have you tried them?

https://www.qualtrics.com/community/discussion/comment/34479#Comment_34479Ending the survey is just one of many possible scenarios . My question is about changing the survey flow in general if the button is clicked

Then the answer would depend on the kind of change you are looking for. Based on your requirements you could use skip logic, table of contents or branch logic.
If its just about creating a clickable button/link then, Google creating an HTML button or hyperlinks and paste that into your question HTML. However, to get some help about what you want to get done, you'll have to be more specific.

https://www.qualtrics.com/community/discussion/comment/34483#Comment_34483If the 'notify webadmin' is clicked, the survey should jump to a special block, which includes a question with text entry and is followed by a customized survey exit. The block will not be the part of the normal survey flow.
The design and visual appearance of the button does not matter. It can be just a clickable link. However, it will be located in the middle of the question, not the end. See below the question text with the button/link:
"If you have found a discrepancy/error within the form, or if you believe that the form is malfunctioning in any way, please notify webadmin . Your message will be promptly reviewed and the form will be updated as nessesary. Bla-bla-bla"

By clicking a button, you could set an embedded data. Then you could use branch logic to change where the respondent goes based on that data. The support pages have details on both.
A simple implementation of that would go something like this:
Question HTML:

If you have found a discrepancy/error within the form, or if you believe that the form is malfunctioning in any way, please   notify webadmin . Your message will be promptly reviewed and the form will be updated as nessesary. Bla-bla-bla

notify 

> By clicking a button, you could set an embedded data. 
> Then you could use branch logic to change where the respondent
> goes based on that data.
>
Let's say the question with is located in block A.
So, I will have to split block A into two (sub)blocks (call them 'C' and 'D') and insert the branch logic immediately after block 'C' where the question with is located.
Correct?
Thus, If I need to add the same button into a few more survey questions, then I will again have to split each such block into two and insert the branch logic in between.
Correct?
Additionally, will clicking the button instantly trigger the branch logic? Or only after the respondent moves to the next question?