Need help on If condition

Here is one method.

Read the notes in the M Code to understand the algorithm

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Reference", type text}, {"Amountindoccurr", type number}}),
    
//Add shifted columns to easily access current and subsequent rows
    #"Add Shifted Columns" = Table.FromColumns(
        Table.ToColumns(#"Changed Type") &
        {List.RemoveFirstN(#"Changed Type"[Reference],1) & {null}} &
        {List.RemoveFirstN(#"Changed Type"[Amountindoccurr],1) & {null}},
        type table[Reference=text,Amountindoccurr=number, Shifted Reference=text, Shifted Amountindoccurr=number]),

//Apply your logical equation
    #"Add T/F" = Table.AddColumn(#"Add Shifted Columns","T/F", each 
        (Text.Length([Reference]) - Text.Length([Shifted Reference]) <=2) and 
            (Text.Length([Reference]) - Text.Length([Shifted Reference]) <> 0) and 
            (Number.Abs([Amountindoccurr]) = Number.Abs([Shifted Amountindoccurr])) and 
            (Text.Contains([Shifted Reference],[Reference], Comparer.OrdinalIgnoreCase)),
         type logical),

//Remove the shifted columns
    #"Removed Columns" = Table.RemoveColumns(#"Add T/F",{"Shifted Reference", "Shifted Amountindoccurr"})
in
    #"Removed Columns"

What is the expected result for the first row?

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("jZS7TgMxEEX/Zesksr0eP0q0oaAACQqEFOX/fwOPKSDJPSvSZc4eW7oz48tlCeNXWnp5Ww7LsRZr/WTL9XAL7uvVP47NSvgtRfNiajHZ3+KTrH48f466Km+vCM501EAbW9s8EsW9C/fheffcf1CA7zvoiw59vK7VNffjT2Pj+Nsf6zflHtYQa/Jyyr2d0h2Y8Uu0krOyk8nJ7Bg5xk4hp7BTyansNHIaO52cDo5l044DdIruqQNwSii6Pw7Y0f1xwI7ujwN2dH8csKP744AdnbUDdGoApwZ2IjmRHd1TB+zoPXXADs0B7ulANAe4pwPRHOCeDkRzQHuaR0XeMwE78p4J2JHzNgE7ct4mQMdk1hOwQxkYZ2CUgXEGRhkYZ1DkjE7AjpzRCdih3OitckS50Vs1kN7TCdihDGhPHVEGtKc5x/Xm3bl+Aw==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Reference = _t, Amountindoccurr = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Amountindoccurr", type number}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1, Int64.Type),
    #"Added Custom" = Table.AddColumn(#"Added Index", "Check", each 
if Text.Length(#"Added Index"{[Index]-1}[Reference])-Text.Length([Reference])<=2 
and Text.Length(#"Added Index"{[Index]-1}[Reference])<>Text.Length([Reference])
and Number.Abs(#"Added Index"{[Index]-1}[Amountindoccurr])=Number.Abs([Amountindoccurr])
and Text.StartsWith([Reference],#"Added Index"{[Index]-1}[Reference])
then true else false)
in
    #"Added Custom"