Pre-filtering nested tables before expanding

There's no GUI button but the code looks just like any other filter step.

Here's an example you can paste into the Advanced Editor of a new blank query:

let
    Source =
    #table(
        type table [Date = date, Budget = number, Record = record],
        {
            {#date(2019,09,15), 500, [Code="001", Text="abc", Value=3]},
            {#date(2019,10,15), 600, [Code="002", Text="xyz", Value=5]},
            {#date(2019,10,31), 400, [Code="003", Text="ijk", Value=8]}
        }
    ),
    #"Filtered Rows" = Table.SelectRows(Source, each ([Record][Code] = "003" or [Record][Value] = 5))
in
    #"Filtered Rows"

Preview: