Oracle SYS tables question?

 I am looking for the following info from our database:

 Please point to the sys tables or views which can give me this info:

1) We need to find all objects that use a certain function/procedure, or view etc.

     Example:-  If I give a function name "XYZ" , the sys table needs to show me what all
                      objects are being used in that function.

     Example:-  If I give a table name "ABC"  , the sys table needs to show me where all
                      this object is being used ( function,view,procedure)

2)  If I give a column_name it needs to show me where all this similar column_name is being
     used in my entire database objects ?


 Give me the SYS view names with query if possible to find the answers for the above questions.

 Any commercial tool is also good -if there is one to make our life easier.