Add multiple named ranges in data validation for selection

I know in one of my past threads I have an answer that would probably solve this for me, but after performing a search I just can't find that thread.

I use the below in a custom list in data validation which works fine for two named ranges, but I need to add more references than two.

=IF($D$8="CIV",DV_CIV,DV_CME)

I tried something like

=LOOKUP(D8,{"CIV","CME","MIL"},{DV_CIV,DV_CME,DV_MIL})

but data validation does not accept this.

Can I get a shove in the right direction?