PL/SQL :: Variable To Pass A List Of Names Between 2 Tables

I am trying to pass a list of names from one table as a variable to another table and trying to find the Highest level they exist at in the hierarchy. I am having some troubles with the variable and need some guidence and also if this should be a procedure or not.

this is what i have now :

Variable man_name Varchar;
exec :man_name = (Select full_name from direct_manager_report)
UPDATE direct_manager_report
Set Manager_level_number =

[Code]....

Let me know what modifications have to be done for this the variable to get the name from table 1 and find the manager level from table 2 and populate it back in table 1.