how to delete the blank page in the reference topic

[iris]

Hi expert,
I found after the topic there is a blank page. Please see the below picture. Between Topic 3 and Topic 3.1 have a blank page.

2.png

But I don't want this blank page. I'd like the next sub-topic just close to the major topic, like this picture.

Could you please give some guidance? Thanks

3.png

[julien_lacour]

Hello,

Could you indicate which Oxygen version you are using and which transformation scenario you are running?

Regards,
Julien