Posting this because it took me way too long to figure out. If you’re using a function like Physics2D.OverlapCircle() or Physics2D.OverlapArea(), one of the function parameters is a layermask int. I’m not well-versed in how a layermask translates into an int, but after a bunch of research I found this works:

1 << LayerMask.NameToLayer("LayerName")

Just drop this into the function argument and it works. I prefer to refer to my layers by name instead of int (and I’m sure others do too), so hopefully this helps someone.