A client has a GI with a vendor parameter. When you click on the dropdown it also shows all the users as they also have a baccountid. I need to be able to put a condition on the parameter as putting in a normal condition in the conditions tab only affects the resulting data.

The relations is this:

Parameter:

In the dropdown on the GI they need to only see from where the vendors start, in this case the naming convention all start with V-, where as the ones above are all employees.

Would this require customization?