Instead of attaching a worksheet based on the first level of custom field selected allow us to add worksheet based on a select made to the inputs of custom field.

Example:
Current = Attach worksheet to custom field "Computer Repair"
Suggestion = Allow us to attach worksheet to a select field under the Computer Repair Tag, ie "Computer Repair: Virus Removal" or "Computer Repair: Software Install" Both workflows would have different information needed to be captured.