Loop and merge customized?

Is there an unstated reason you want to use Loop & Merge here? If not, that feature is too robust for this case. Unless the scenario above is extremely simplified compared to your actual one, you can probably do what you need by using Display Logic to show the follow-up questions instead of Loop & Merge.

https://community.qualtrics.com/XMcommunity/discussion/comment/43461#Comment_43461Hey,
thank you for your answer. Yes it's simplified. I give them 10 options, 5 of them are the ones that I am interested in. In sum I have 5 thematic categories and each category will have 10 items each of which only 5 are interesting for further questions . So in sum I would need 25 questions with display logic, which I actually want to avoid.
I really do not know why you can't choose which of the selected choices you want to ask further. It doesn't seem to me like my use case is all that abitrary.

In that case I would suggest working in the Survey Flow, and setting up separate blocks for each of the 5 options that you want to ask follow-up questions about. Use Branch Logic to display each block as appropriate. That way you would only have to set up 5 logic rules instead of 25.

Hey Matthew,
I don't know if I get this right, but these 10 options are always different. I could not make 5 blocks out of it.

OK. It's hard to tell for sure without an illustration of the first question, but this sounds a little bit different, and maybe a lot more complicated, than the original example. If you haven't already, check out this support article about Using Logic in Loop & Merge Blocks. If that doesn't help, then it may be that Loop & Merge is not designed for this kind of scenario.