How to create two types of sign-in process in SocialEngine?
You can easily do this if you create two types of Profile Types in your SE site. This is done from the Admin section > Settings > Profile Questions > Create New Profile Type (1).
Once you have named the two Profile Types in accordance to your two user types you want, you can specify separate Question types for their sign-in process from the same page > Add Question (2). Just make sure you have selected the desired Profile Type from the Editing Profile Type drop-down menu (3) first.