The Revit TV Drawing Manager main screen is effectively a drawing list
You can organise drawings into groups by any of the column
title headings just by dragging the column heading onto the space above
That column heading can still be used for sorting and filtering.
The groups of drawings are then expandable/collapsible in the list by clicking on the + or – to the left of the group heading.
NB. When you scroll down a list the group heading disappears off screen so it may not be easy to see which group you are in.
To remove the grouping, drag the column heading back to its original location amongst the other column headings.
This technique of grouping is particularly useful when you have linked projects in RTV Drawing Manager, as the Revit project name appears as a column heading