extract text after delimiter using a delimiter column

If you want result in another column and 

= Text.AfterDelimiter([target],[delimiter])

For in column replacement, insert following statement i.e. not create another column

= Table.ReplaceValue(Source,each [target],each Text.AfterDelimiter([target],[delimiter]),Replacer.ReplaceValue,{"target"})

See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WSqxJUtJRqlGK1YlWSk7xzNLJzskFCugoxcYCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [target = _t, delimiter = _t]),
    Custom1 = Table.ReplaceValue(Source,each [target],each Text.AfterDelimiter([target],[delimiter]),Replacer.ReplaceValue,{"target"})
in
    Custom1