I guess your are looking for SearchParameters.SearchSort, defines the order in which search results are displayed. by default it is
You can specify one or more search fields (separated by commas) according to which the results will be sorted. The default order is ascending — you can reverse the order by adding the DESC keyword (e.g. articleid DESC).
Note: Fields must be set as Searchable in the smart search field configuration of individual object types to be usable in search sort expressions.
Yes you can
SearchSort = "name ASC, then by date DESC", but name and date must be searchable
P.S. If you encounter the "
Field <fieldname> does not appear to be indexed" error when using multiple indexes, try specifying the type of the field, for example: (date)documentcreatedwhen