You do not have to use any tables except the primary company table and the employees table, because the employees table contains all the data from all the managerial tables:

select c.company_code, c.founder, count(distinct e.lead_manager_code), count(distinct e.senior_manager_code), count(distinct e.manager_code), count(distinct e.employee_code) from company as c, employee as e where e.company_code = c.company_code group by c.company_code, c.founder order by c.company_code;