Enable a search field

You must enter on the form where you click on the "fields" tab, where you will see the different metadata, you have the option to filter for a quick search and the field will appear on the left side of the screen. 

After you have selected the field you need to enable the search you will be taken to the field information, where you will see a button called "Searchable" which you must activate to appear in the search bar. 

Return to the documents page and look for the field above the bar