Create PDF from multiple files - only bookmarks from original files

I'm having a hard time finding an answer to my question. Here's the situation:

I'm trying to make one pdf from multiple pdf's in Acrobat Pro using the create pfd from multiple files function. When the combined pdf is created, top level bookmarks are created for each file name. Below the top level bookmarks, the original bookmarks from the files are present. 

My ideal situation is to have the bookmarks from the original files only and lose the filename bookmarks but I can't find an option. Now I am faced with a lot of manual labour.