Gitlab merge two branches
<p>We have created 'dev' branch from the 'master' and have been working on the 'dev' branch. We have not merged the 'dev' to 'master' yet. Also at the same time we have created 'preprod' branch from the 'master' and working on the 'preprod' branch changes. We have not merged the 'preprod' to 'master' yet. </p>

<p>Now what we are trying to achieve is to merge the 'preprod' changes alone to 'dev'. I tried this by creating a merge request through Gitlab and approved it. What I found is the changes in the 'dev' code was also moved to 'preprod' and vice versa. I do not want the 'dev' changes to be moved to the 'preprod' by any chance. How can i accomplish this ? </p>