To be able to use the Request module in N-OC you have to create rules for the different crew groups.
For details see How to do Requests
For this dialog to work you need to have Association rights.
For each filter you can make a sub-group that will apply to the contract percentage.
Note: All fields must be filled, min. requirement is 0 (zero).
Note: You have to save the sub-group before you can save the dialog.