d = {'key1': {'foo': 1233, 'bar': 1234, 'baz': 122}, 'key2': {'foo': 113,
    'bar': 333}}
keys = (list(x.keys()) for x in d.values())
common_keys = set(next(keys)).intersection(*keys)
{k: {k_: v[k_] for k_ in common_keys} for k, v in d.items()}
new dictionary with common subkey