Excel VBA Hide Rows Based Upon List Selection Performance

Even though the handler doesn't modify any cells, it's usually a good idea to disable application events when handling a worksheet's Change event. You can do this by setting Application.EnableEvents to False at the top, and back to True before exiting - preferably with proper error handling, so the initial state is always restored whether there's a run-time error or not.

I mentioned Rubberduck in a comment earlier; its code inspections would have warned you about implicit qualifiers everywhere you're invoking the worksheet's Range property: Range(...) is implicitly Me.Range(...) here, meaning we're looking for cells on the same sheet as Target, i.e. the sheet that's handling this Change event.

However... not all worksheet accesses are implicitly qualified: ActiveWorkbook.ActiveSheet.Columns("R").Cells refers specifically to the active sheet, which may or may not be the same sheet. If there's code anywhere that can change cell $D$1 while another sheet is active, then that's a bug, because you'll be iterating cells and hiding rows on a worksheet you're not intending to modify here.

You'll want to restrict the number of cells you're looking at, and avoid iterating every single cell in any given column - I suspect that's where most of the performance is getting lost, churning through hundreds of thousands of empty rows.

Consider first finding the last row you're interested in, and you can likely leave out the parameterless .Cells call:

For Each cell In Me.Range("R" & lastRow)
    ...
Next

You're reading cell values and comparing them to string literals without first validating that you can actually do that:

If cell.Value <> "AP" Then

This is dangerous: you'll get a type mismatch run-time error if a cell ever contains a worksheet error (like #N/A, or #VALUE!). Use IsError| to validate cell values first - because If` conditions don't short-circuit in VBA, that means nesting the conditions:

If Not IsError(cell.Value) Then
    If cell.Value <> "AP" Then
        ...
    End If
End If

But why are we using Value here but Text everywhere else? Pick one, and stick to it!

Now, if that ... inside the conditional block remains "hide that entire row", there's a missed opportunity to hide all the interesting rows at once! Use Union to build yourself a range as you traverse the cells, as if you were holding the Ctrl key to select rows; then you hide all the rows of the combined range, and benefit from only accessing the worksheet once.

Lastly, since all the conditions are checking different possible values for Target.Text, consider using Select Case Target.Text instead, to reduce redundancy and only read the value once:

Select Case Target.Text
    Case "ALL"
        '...

    Case "OVERRIDES"
        '...

    ...
End Select
```