You can use an existing global variable, a context variable defined in your Job, or a Repository-stored context variable applied to your Job in any component properties field.
In the relevant Component view, place your mouse in the field you want to parameterize and press Ctrl+Space to display a full list of all the global variables and those context variables defined in or applied to your Job.
The list grows along with new user-defined variables (context variables).
Double-click the variable of your choice to fill it in the field.
In database output components, when parallel execution is enabled, it is not possible to use global variables to retrieve the return values in a SubJob.