You can find references to a table in all the recently run SQL with a query like:

select * from v$sql
where  upper ( sql_text ) like '%TABLE_NAME%'
and    upper ( sql_text ) like '%COLUMN_NAME%';

And you can find where it's used in PL/SQL code with a query like:

select * from dba_statements
where  text like '%TABLE_NAME%'
and    text like '%COLUMN_NAME%';

Note - you need to be on 12.2 or higher and have compiled the code with these settings first:

ALTER SESSION SET plscope_settings='identifiers:all, statements:all'

These will give false positives - statements that include the table and column name but reference a different table/column or just have it in comments. It also won't show you references if the column is accessed via a view. You can find views that use it with:

select * from dba_views
where  upper ( text_vc ) like '%TABLE_NAME%'
and    upper ( text_vc ) like '%COLUMN_NAME%';

These methods will also overlook rarely run instances in application code, scripts, etc.

and based on that change the where clause ?

Change how and why?