Hide rows based on text criteria

Try:

Sub foo()
    Dim ws As Worksheet
    Dim rng As Range
    Dim c As Range
    
    For Each ws In ThisWorkbook.Worksheets
        Set c = ws.Columns(2).Find("Section")
        If Not c Is Nothing Then
            Set rng = Range(c.Offset(1, 0), ws.Cells(Rows.Count, 2).End(xlUp))
            Set c = Nothing
            For Each c In rng
                With c.MergeArea
                    .EntireRow.Hidden = Not .Cells(1).Value = Worksheets("Refresh").Range("A1").Value
                End With
            Next c
        End If
    Next ws
End Sub

Just a comment.

You are making life complicated by merging cells. Most of us avoid them like the plague - they are just too much trouble and cause too many problems. Apart from which any analysis is seriously compromised.

I'd urge you to change your layout and capture data in a normalised 2 dimensional data table. In your case have columns for

Date
Customer
Section
Data
Value
'Sheet Name' i.e. AAA, 000 or whatever this analysis is meant to record

and make each piece of data a record.

In addition to simplifying any analysis you'll open up the whole wonderful world of the Pivot Table functionality