List.Accumulate or what?

Hello, greta 

let
    Source = simplified_table,
    z = Table.Group(
        Source, {"prog"}, 
        {{
            "on_hold", 
            each List.PositionOf(
                Table.Sort(_, {"index", Order.Descending})[status],
                "on hold", 
                Occurrence.First, 
                (x, y) => x <> y
            )
        }}
    )
in
    z

greta I did not consider the case when all values are On Hold. Try this instead:

let
    Source = Lista_OnHold,
    z = Table.Group(
        Source, {"MercatusCode"},
        {{
            "On_Hold",
            each 
                [lst = Table.Sort(_, {"Index.1", Order.Descending})[ProjectStatusInternal.1],
                pozz = List.PositionOf(lst, "On Hold", Occurrence.First, (x, y) => x <> y),
                zz = if pozz = -1 then List.Count(lst) else pozz][zz]
        }}
    )
in
    z