It looks like I'm about to apply for a postdoc position to go back to my former PhD supervisor, with only one PI in between.
Normally as a Postdoc going for a 2nd (or 3rd depending on how you count it) position, the PhD supervisor would be a good person to ask for a reference (one of 3 in this case). My supervisor was also the last person I worked for before my current PI - again, last but 1 boss would be a sensible reference.
But what if the position being applied for is working for the former PhD supervisor? It seems obvious to me that you can't ask someone to for a reference when they're the one hiring. In this case everyone I'd ask for a reference from my PhD days is on the hiring committee. Is the only course of action to not have any references from the PhD period?
In this case I'm on good terms with everyone, but have a fairly limited network (partly because of the geographic limitations that are why I'm applying to go back there); I'm moving on because of funding running out so my PI knows I'm applying for stuff (and I've actually asked them pretty much this question).