How to use if expressions in an object pattern field?

[AiyaPK]

Hi!
Suppose I'm pulling in an alembic file that holds an assortment of primitives of varying LODs.
I'd like to write an expression in the "objectPattern" field of the Selection tab in the Alembic file sop, such that it filters for the highest LOD available.
So if it finds *geo_hi* in the path, it should just select for that, otherwise, fallback to *geo_mid*, then *geo_lo*.
I tried to do a simple test with an expression but didn't work as expected...
I wrote
if(*geo_abcde*, *geo_hi*, *geo_lo*)
geo_abcde doesn't exist (since at the moment my test file has all 3 LODs), so I would've expected to default to geo_lo...  but instead, it just filters for geo_hi
Did I write something wrong? or do if statements not work like this?

Also, I would've thought I could do something like:
if(*geo_hi*,*geo_hi*,( if(*geo_mid*,*geo_mid*,*geo_lo*))
as a rudimentary fallback expression, which also doesn't work, given the above simpler case already doesn't work.