Add Additional Attributes to NIR (new item request) Setup flow

Summary

Unable to select Item:Additional Attributes for addition to NIR flow

Content

Hello, 

Please reference attached image, 'Additional Attributes' and 'Associated Entity'.

I would like to know how to select the Additional Attributes page / group and add the attributes within that group to our NIR setup process. 

On the Definition Workflow Details page I am not able to select the Additional Attributes page as an Associated Entity. 

I would think since the Additional Attributes Page is on the PIM screen I would be able to select the group to be a part of the NIR flow. 

Any direction on how to select this group for our NIR process would be very helpful.