Oracle SQL Developer: 'All Source Lines' in 'Find Database Object'
I'm going to answer your question based on version 18.2.

Searching source code in an Oracle Database via SQL Developer:



We automatically wildcard your search string - so you can search db object names, like tables named 'EMP' and also look for that string in your database code. We also make sure the case of the text isn't an issue.

Now, what do we consider 'source code?'


All Source Lines: this is the ALL_SOURCE view, in other words, the PL/SQL code you have access to
All Views - the SQL contained in the definition of your View and Materialized Views
All Statements - new for 12cR2 databases, this is the SQL statements collected by PL/Scope via the pl/sql compiler for your pl/sql code
ORDS - the code used to define your RESTful Services


I talk about the search feature here and provide a video demo.