Turning PIVOT query into table function - sql

Question

Following up on BigQuery pivot on more fields, based on the suggestion by the genius Mikhail, I was wondering if the following 'pivot-like functionality' could be turned into a table function. Here would be an example:
The query from the currently accepted answer is:
select
(case when grp_set & 1 > 0 then Reseller end) as Reseller,
(case when grp_set & 2 > 0 then ProductGroup end) as ProductGroup,
(case when grp_set & 4 > 0 then Product end) as Product,
(case when grp_set & 8 > 0 then Year end) as Year,
(case when grp_set & 16 > 0 then Quarter end) as Quarter,
(case when grp_set & 32 > 0 then Product_Info end) as Product_Info,
sum(Revenue) as Revenue,
sum(Units) as Units
from `first-outlet-750.biengine_tutorial.Product`, unnest(generate_array(1, 64)) grp_set
where Year IN (2020) and Quarter in ('Q1', 'Q2')
group by 1, 2, 3, 4, 5, 6
having not (Quarter is null and Product_Info is not null)
and not (Year is null and Quarter is not null)
and not (ProductGroup is null and Product is not null)
order by 1, 2, 3, 4 , 5, 6
And I'm wondering if a table function could be created along the lines of:
PIVOT(
[row_agg1, row_agg2, ...],
[col_agg1, col_agg2, ...],
[agg_val1, agg_val2, ...]
)
So the above query could hopefully be translated into something like:
SELECT
*
FROM
PIVOT(
[Reseller, ProductGroup, Product], -- rows
[Year, Quarter, ProductInfo], -- cols
[SUM(Revenue), SUM(Units)] -- vals
)
A few things that I think might be a bit tricky:
Where does the actual table go in the FROM clause?
How would aliases work? For example, what if we wanted SUM(Revenue) to show up as TotalRev -- how to easily be able to refer to that in the main SELECT clause to be able to alias it if not just doing a SELECT * ?