How to make visibility for flex-fields in 'Document Records' Landing page.

Requirement is when we land into Document of Record page, we see predefine document type in the list (previously added to the employee) in these document type on right side we see a drop arrow of 'Expand' when clicking on that expand symbol, we see additional details like document type code , Number of attachments, similar like these details we want that we can see flex field details in the expanded section without entering inside the document type.