You cannot search across tables, but you may create a view to join the tables first and use it as the master table (you can select just the master table fields to show).
I have created a view and make it as Master Table.
It show correctly for those records which have only 1 records in the Details Table.
But if there is more than 1 records in Details Table for the record in the Master Table
then it show more than 1 records with the same data in the Master List Page.