Duplicate filter

My interpretation of your question in this video resulting in the following code (the first line was created when I entered the data before I started the recording):

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45W8k0sSk7NcUotTVfILFbIz8upVEgtSy1SKMlILUpVitUhRoVbak5mRbyBpYEpSEUeBbIYpscCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [Name = _t]),
    #"Filtered Rows" = Table.SelectRows(Source, each Text.EndsWith([Name], "only ever there")),
    #"Kept Duplicates" = let columnNames = {"Name"}, addCount = Table.Group(#"Filtered Rows", columnNames, {{"Count", Table.RowCount, type number}}), selectDuplicates = Table.SelectRows(addCount, each [Count] > 1), removeCount = Table.RemoveColumns(selectDuplicates, "Count") in Table.Join(#"Filtered Rows", columnNames, removeCount, columnNames, JoinKind.Inner),
    #"Added Custom" = Table.AddColumn(#"Kept Duplicates", "Custom", each {1..2}),
    #"Expanded Custom" = Table.ExpandListColumn(#"Added Custom", "Custom"),
    #"Removed Columns" = Table.RemoveColumns(#"Expanded Custom",{"Custom"})
in
    #"Removed Columns"