from sqlalchemy import create_engine, Table, Integer, MetaData, Column, select, func
from sqlalchemy_bigquery import STRUCT

engine = create_engine(f"bigquery:///tmp", echo=True)
metadata = MetaData()
table = Table(
    "table",
    metadata,
    Column("id", Integer, primary_key=True),
    Column("nested", STRUCT(x=Integer))
)

query = (
    select(
        table.c.nested.x.label("x"),
    )
    .group_by(
        "x"
    )
)
print(query.compile(engine))

UnsupportedCompilationError: Compiler <sqlalchemy.sql.compiler.StrSQLCompiler object at 0x102f35f00> can't render element of type <function struct_getitem_op at 0x30532a9e0> (Background on this error at: https://sqlalche.me/e/14/l7de)