main_query = Template("""
    WITH cte1 AS (
        SELECT ... 
        FROM table3
        JOIN ({{subquery}}) AS table_x
        ON ...
        WHERE ...),
    cte2 AS (
        SELECT ... 
        FROM table4
        JOIN ({{subquery}}) AS table_x
        ON ...
        WHERE ...),
    ) 
    SELECT 
        ... 
    FROM cte1 
    JOIN cte2 
    ON ... 
    WHERE ...
""").render(subquery=base_query)