Using JPA, here is how I created a predicate that searches a JSONB column for any of the provided keys.

jsonb-search-predicate.java

builder.equal(
  builder.function(
    "JSONB_EXISTS_ANY",
    Boolean.class,
    root.get("nameOfJsonbColumnToSearch"),
    builder.function(
      "string_to_array",
      String.class,
      builder.literal(String.join(",", setOfValuesToSearchFor)),
      builder.literal(",")
    )
  ),
  true
)

/shrug

doesn't seem proper in retrospect. i mean, it works, but the point of JSONB is to be able to efficiently get keys. i couldn't find a way to do it at the time, hence this hack.