Number SSRS pages based on grouping

I have a SSRS report which needs to have paging like (1 of 2, 1 of 3)

currently using

=Globals!PageNumber & "of " & Globals!TotalPages

gives me (1 of 5) which i know is the correct behaviour

Everywhere i see the solution is Group Properties > Page Breaks > ResetPageNumber

I dont get that option though, the pagebreak options i get are

• Between each instance
• Also at the start of a group
• Also at the end of a group

To achieve what i wanted to do i edited the code itself not the rdl design which i had previously wanted to do

<PageBreak>
   <BreakLocation>Between<BreakLocation>
   <ResetPageNumber>True<ResetPageNumber>
<PageBreak>

This allowed me to print the letter's which contained a table of information at the end which was X rows long

So report could be (1 0f 1), (1 of 2, 2 of 2), (1 0f X, X 0f X)