There is now an advanced search tool, find it at https://suttacentral.net/advanced_search
It permits making more precise queries and also searching on fields such as Vol/Page. At the moment advanced search is only for the Sutta database. It cannot be used to search texts or dictionaries. However I expect to add these to the advanced search tool.
Naturally the advanced search will probably only be of interest to scholars, and will probably only be useful when you can’t make the default search produce relevant results.