Joining to Queries side by side calculating sales values by year
Use a JOIN clause. So instead of the comma betwee the tables, put FULL OUTER JOIN. And then after A2 put ON A1.Employee = A2.Employee AND A1.Title = A2.Title. 

But a better option might be to use a single query, with:

select 
   concat(e.titleofcourtesy,' ', e.firstname, e.lastname) as Employee, 
   e.Title, 
   sum(CASE WHEN o.ShippedDate between '1996-01-01' and '1996-12-31' THEN (od.unitprice * od.quantity) - (1 * od.discount) ELSE 0 END) as TotalSalesValue_1996, 
   sum(CASE WHEN o.ShippedDate between '1997-01-01' and '1997-12-31' THEN (od.unitprice * od.quantity) - (1 * od.discount) ELSE 0 END) as TotalSalesValue_1997
from employees as e 
inner join orders as o on o.employeeid=e.employeeid
inner join order_details as od on od.orderid=o.orderid
where o.ShippedDate between '1996-01-01' and '1996-12-31'
group by e.title, concat(e.titleofcourtesy,' ', e.firstname, e.lastname);