Sub Macro1()
'Graham Mayor - https://www.gmayor.com - Last updated - 25 Sep 2019
Dim oSource As Document
Dim oTarget As Document
Dim oRng As Range, oTargetRng As Range
    Set oSource = ActiveDocument
    Set oTarget = Documents.Add
    Set oRng = oSource.Range
    With oRng.Find
        Do While .Execute(findText:="the supplier")
            oRng.Start = oRng.Sentences(1).Start
            oRng.End = oRng.Sentences(1).End
            Set oTargetRng = oTarget.Range
            oTargetRng.Collapse 0
            oTargetRng.FormattedText = oRng.FormattedText
            oRng.Collapse 0
        Loop
    End With
    Set oRng = Nothing
    Set oTargetRng = Nothing
    Set oSource = Nothing
    Set oTarget = Nothing
End Sub