deno test --filter doesn't seem working for subtest names

[kt3k]

Assume we have a.js, like:

Deno.test("1", async (t) => {
  await t.step("2", () => {
  });
  await t.step("3", () => {
  });
});

If we filter with 2, then it can't find any test case:

$ deno test --filter=2 a.js

ok | 0 passed | 0 failed | 1 filtered out (1ms)

Is this by design, or should this execute subtest of matching name?

related: denoland/std#6063