index match multiple sheets and then sum the value

AKuma0411 The FILTER function only accepts three arguments. The basic syntax is:

=FILTER(array, include, [if_empty])

To SUM the results from multiple worksheets, try the following:

=SUM(
   FILTER(UEPL_Final!$N$6:$N$200, UEPL_Final!$E$6:$E$200 = $C11, 0),
   FILTER(LEPL_Final!$N$6:$N$200, LEPL_Final!$E$6:$E$200 = $C11, 0),
   FILTER(IMN_Final!$N$6:$N$200, IMN_Final!$E$6:$E$200 = $C11, 0)
)

If the worksheet tabs are arranged in order from left to right, you could also try using the VSTACK function to reference and filter all three sheets at once. For example:

=SUM(FILTER(VSTACK(UEPL_Final:IMN_Final!$N$6:$N$200), VSTACK(UEPL_Final:IMN_Final!$E$6:$E$200) = $C11, 0))

Or, to improve readability, use the LET function to define the two arrays first:

=LET(
   array1, VSTACK(UEPL_Final:IMN_Final!$N$6:$N$200),
   array2, VSTACK(UEPL_Final:IMN_Final!$E$6:$E$200),
   SUM(FILTER(array1, array2 = $C11, 0))
)

I hope that helps to clear things up. Cheers!