Hmmm I can't quite do it in one formula, but there are a couple of other ways I can think of. Let's say you're typing a name into cell B2 on a tab named "FrontTab"
1. You could put in each data tab into cell A1 (for example) something like
=IFERROR(INDEX(nameRange,MATCH(FrontTab!B2,discountRange,0)),FALSE)
Then, where ever you like on the front tab,
=MAX('firstTabName:lastTabName'!A1)
2. If you don't want to go into each tab individually, you could have a list on the front tab of all the other tabs names, such as this:
[TABLE="class: grid, width: 172"]
<tbody>[TR]
[TD][/TD]
[TD]A[/TD]
[TD]B[/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]2[/TD]
[TD]Search:[/TD]
[TD]bec[/TD]
[/TR]
[TR]
[TD]3[/TD]
[TD]Discount rate:[/TD]
[TD="align: right"]Formula2[/TD]
[/TR]
[TR]
[TD]4[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]5[/TD]
[TD]Sheet1[/TD]
[TD="align: center"]Formula1[/TD]
[/TR]
[TR]
[TD]6[/TD]
[TD]Sheet2[/TD]
[TD="align: center"]""[/TD]
[/TR]
[TR]
[TD]7[/TD]
[TD]Sheet3[/TD]
[TD="align: center"]""[/TD]
[/TR]
[TR]
[TD]8[/TD]
[TD]Sheet4[/TD]
[TD="align: center"]""[/TD]
[/TR]
[TR]
[TD]9[/TD]
[TD]Sheet5[/TD]
[TD="align: center"]""[/TD]
[/TR]
[TR]
[TD]10[/TD]
[TD]Sheet6[/TD]
[TD="align: center"]""[/TD]
[/TR]
</tbody>[/TABLE]
Then, against each tab name, have discount results using:
Formula1: =IFERROR(INDEX(INDIRECT("'"&A5&"'!discountRange"),MATCH($B$2,INDIRECT("'"&A5&"'!nameRange"),0)),FALSE)
And in B3
Formula2: =MAX(B5:B10)