FilterWithAccessor.sc

case class Foo (
  fooInt: Int,
  fooString: String
)

val theFoos = Seq(
  Foo(0, "hello"),
  Foo(1, "goodbye"),
  Foo(2, "")
)

def filterFoos[T](accessor: Foo => T, predicate: T => Boolean) = (f: Foo) => predicate(accessor(f))

// alternately (and exactly the same as the above):
// def filterFoos[T](accessor: Foo => T, predicate: T => Boolean)(f: Foo) = predicate(accessor(f))


val oddFilter = filterFoos[Int](_.fooInt, x => x % 2 != 0)
theFoos.filter(oddFilter)


val stringNonEmpty = filterFoos[String](_.fooString, _.nonEmpty)
theFoos.filter(stringNonEmpty)

Er, not "exactly the same"

When using the commented out form of filterFoos you would need to explicitly trigger eta expansion with a trailing _:

val oddFilter = filterFoos[Int](_.fooInt, x => x % 2 != 0) _