**Use case**
`SELECT POSITION('/' IN s) FROM (SELECT 'Hello/World' AS s);`

The same as `position(s, '/')`

ParserOrderByExpressionList columns_order_by;
    if (keyword_partition_by.ignore(pos, expected))
    {
        ASTPtr partition_by_ast;
        if (columns_partition_by.parse(pos, partition_by_ast, expected))
        {
            function->children.push_back(partition_by_ast);
            function->window_partition_by = partition_by_ast;
        }
        else
        {
            return false;
        }
    }
    if (keyword_order_by.ignore(pos, expected))
    {
        ASTPtr order_by_ast;
        if (columns_order_by.parse(pos, order_by_ast, expected))
        {
            function->children.push_back(order_by_ast);
            function->window_order_by = order_by_ast;
        }
        else
        {
            return false;
        }
    }
    if (pos->type != TokenType::ClosingRoundBracket)
    {
        expected.add(pos, "')'");