Hash search works by taking your search query, and finding all publicly exposed data entries associated with that hashed password:
for example you search: '*hashed pasword*' => found: user@gmail.com, user2@yahoo.com, user3@outlook.com
The main use of hash search is taking a hashed password from one result, and searching it with hash search to find associated data. Example:
Step 1 (email search): user123@gmail.com =>
hashedpassword123
Step 2 (hash search): hashedpassword123 => user123alt@gmail.com...
Make a test hashed password search