Setting up rates for Domestic Partner

Summary:

My company will be offering Domestic Partner coverage this year during Open Enrollment. I have created two new options Employee+Domestic Partner and Employee+Child(ren)+Domestic partners to add to our Medical, Dental and Vision plans.

What I'm stuck on is how to set up the Standard rates to attach to the new Payroll elements I built as well. I know that the Employee will be Pre-Tax, the DP portion will be After-Tax, ER Nontaxable and ER taxable. To also add a layer of complexity we also use Variable Rates for the Medical and Dental. I've seen some things posted on this but didn't know if anyone could share detail screen shots or step by step instructions on the rate set up.