I'm grouping on order type which is using the following formula:
global stringvar ordertype;
IF {PO.LOCATION} like "??P??" THEN 'AUTO'
ELSE IF {POLINESRC.REQ_LOCATION} like "??X??" THEN 'SCAN'
ELSE 'OTHER';
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The formula I'm using to get the Qty Var is '{@OneMoQtyTotDisplay} - {@avg3moqty}'
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The formula for {@OneMoQtyTotDisplay} is:

WhilePrintingRecords;
Global NumberVar OneMoQtyTotByItem;

{PO.ITEM};

OneMoQtyTotByItem;

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This is using the other following formula's.
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This is placed in the details:

WhilePrintingRecords;
EvaluateAfter({@onemonthqty});

Global NumberVar OneMoQtyTotByItem;
Global NumberVar onemonthqty;

{PO.ITEM};

OneMoQtyTotByItem := OneMoQtyTotByItem + onemonthqty;

OneMoQtyTotByItem;

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Reset placed in group header:

WhilePrintingRecords;
//EvaluateAfter({@OneMoQtyTotDisplay});

Global NumberVar OneMoQtyTotByItem;

{POLINE.ITEM};

OneMoQtyTotByItem := 0;
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The {@avg3moqty} formula is 'Sum ({PO.QUANTITY}, {PO.ITEM})/3'




I hope this helps. Thanks

So the group is on Order Type. As DBlank told, I prefer to use a command or Proc for this. DO all the calculations at query level and pull the data to the report. Then its very easy to do sorting in report.


I Assume that you are displaying
SCAN

In Group Header

And the below fields in Details.

40555     5        6     1
40557     8        4     -4
12124     4        8     4

If its the above case, put a record sort on Var formula.

In another case if you have created another group for
Item also and displaying this on header, you have to bypass the group sorting.

Create a Summary for the field to be sorted and put it on Group Footer. Supress the Group Footer. Then on Group Sort Expert add that summary which is pulled in to the group footer. Also put a dummy formula in Group expert for sorting.This will bypass the group sorting.