How may I migrate this kind of question to another discussion group?
- If you have at least 3000 reputation: click the “close” button on the question, select “off-topic”, then “This question belongs on another site in the Stack Exchange network” and the desired target site.
- If you have less than 3000 reputation: click the “flag” button , then select “it should be closed for another reason...”, then “off-topic” and continue as above.
- If the desired site doesn't appear in the list, or if the question is already closed, click “flag”, “other”, and explain what you want a moderator to do and why.
By the way, on Stack Exchange, there are no discussion groups. Stack Exchange is a network of questions and answers sites. Calling them “group” or “site” is a matter of terminology, but the difference between discussion and Q&A is important.
Which group would be better suited to get a correct risk evaluation aware answer with technical details taking into account the basic weaknesses of the targeted OS?
This site is the right place.
But the question you link to is not about getting a risk evaluation. It's about how to accomplish a particular task, and the task is a system administration task, not a security task. This is the job of a system administrator, not the job of a security professional. That's why this question is off-topic here. The question would be on-topic on Super User, a site for computer users and amateur administrators, or possibly on Server Fault, a site for professional system administrators dealing with enterprise software and hardware.
Given that the question has not been answered, migration is overcomplicating things a bit. You might as well repost the question on Super User.