On filter view in AEM DAM asset searching, I want to segregate (using OrderBy) the results based on type - internally they should be alphabetically ordered

The ask is to sort the 'Files & Folders' filtering option in the AEM DAM 'Filters' interface, so that the Folders appears first  (in Alphabetical order) before the loose 'Assets', with loose 'Assets' also listed in Alphabetical order underneath the 'Folders'

Right now, I could segregate the folders based on orderBy=nt:folder, which I added in an overlaid datasource here
/libs/granite/ui/components/shell/omnisearch/datasource/searchdatasource/searchdatasource.jsp, but I could not sort it alphabetical.
If I sort it alphabetical, I can't segregate based on file type (with orderby query predicate). We essentially want both to happen. 

If I write sorting logic in JSP, the problem is that list and card views have 'page limit' and 'offset' so the alphabetical (or) type sorting is not applied on whole search results. Is there a way to achieve this queries possibly?  Or atleast by writing custom that applies whole search results ?

Any suggestions are helpful. 
Thanks