Local then National?

[aephi alum]

I think I see what you're asking...

You're an alum of a local called ABC. You AI into an NPC sorority called XYZ. After you complete the AI process, ABC becomes a colony of another NPC sorority, DEF. DEF issues an invitation to all ABC alums to become alum initiates of DEF. In this case, you have to turn the invitation down because you've been initiated into XYZ and you can't be initiated into two NPC orgs.

Or, you're an alum of a local called ABC. You AI into an NPC sorority, XYZ. After you complete the AI process, ABC suddenly does a whole lot of expansion and is admitted as the 27th (28th, 29th...) NPC sorority. In this case, you have to choose whether you want to be considered a member of XYZ or ABC.

Or (as happened with Beryana) you're an alum of a local called ABC. ABC becomes a colony of DEF, and DEF issues an invitation to all ABC alums to become alum initiates of DEF. You can turn that invitation down, then later pursue AI into the NPC org of your choice.