When you click on the Assign Membership option the first thing you are required to do is to select which organization you are working on. Select the group from the dropdown box and click on the Display button.
Next you're asked to select which semester's roster you want to modify. Select the term and click on the Display button.
At this point you can start adding new members. When you input the Banner ID number into the designated space and move to the next field the name will automatically be pulled up. You are also required to select a status for the individual. Primary and secondary role, however, are optional. For all three of these last choices, if there is not an equivalent status or role in your organization listed then pick the one that best suits that person.