Use this function to set the parameter block to perform an internal search. This function is needed in order to use the internal search operation function, slapi_search_internal_pb().
You would typically create a Slapi_PBlock structure using slapi_pblock_new(), pass that parameter block to slapi_search_internal_pb(), and then pass the same parameter block to actually do the search.
Returned entries are those provided to the entry callback or in the array got with slapi_pblock_get(pb, SLAPI_PLUGIN_INTOP_SEARCH_ENTRIES, &entries)().