Assigning Program's Parameters Dynamically

 Hello everyone,

 If I have 2 parameters for a certain program.
How can I achieve the following scenario :

When I assign a value in a parameter, the second parameter will gets its value will depend on the first value
for example

the second parameter  will get the values as follwoing :
select name
from x
where x.col = value_of_parameter_1


Please respond as soon as possible
Thank you