Filter rows

To filter out the current month, you need to use the Advanced Editor with a line like:

#"Remove Current Month" = Table.SelectRows(#"Previous Step", each [Dates] < Date.StartOfMonth(Date.From(DateTime.LocalNow())))

Replace #"Previous Step" with the obvious.

You could also add a Choose Rows step from the UI, and, in the formula bar, edit what you see to show the above selection criteria.

Here is an example, including creating a column of dates spanning several years, that will return only the rows with months in the current fiscal year excepting the current month:

let
    fyStart=[a=Date.From(DateTime.FixedLocalNow()),
             b=Date.Month(a),
             c=Date.Year(a),
             d=if b < 9 then #date(c-1,9,1) else #date(c,9,1)][d],

//Create table with date column over several fiscal years
    Source = #table(type table[Date=date],List.Accumulate({1..36},{}, 
                    (s,c)=>s & {{Date.AddMonths(#date(2023,1,1),c)}})),

//Select current fiscal year except current month
    #"Current FY" = Table.SelectRows(Source, each [Date]>=fyStart and [Date] < Date.StartOfMonth(Date.From(DateTime.FixedLocalNow())))
   
in
    #"Current FY"

Source Table:

Results: