Because what you are trying to accomplish requires a template customization, we would highly to suggest that you use a child theme. This allows you to make code changes that won’t be overwritten when an X update is released. After your child theme is setup, please review how we recommend making template changes in Customization Best Practices.
Regretfully, this particular customization request is outside the scope of our support as this is not related to an issue with the theme and instead has to do with your customization of it. As such, you will need to investigate this particular issue on your own or seek help from a developer should you not feel comfortable making these changes yourself. If you have any further questions about the theme, we are more than happy to provide you with assistance on these inquiries.
As an alternative and the simplest way, please install Essential Grid plugin. You can install this by going to X > Validation > Extensions. Once Essential Grid plugin is installed, you can create 5 grids that display items from specific authors. You can then create 5 separate 5 pages and insert the respective grid for the specific author page which you have created. To know more about this plugin, please check this out: https://theme.co/apex/forum/t/extension-essential-grid/68
Hope this helps.