I am trying to define a data validation rule for a column in which I would like a dropdown list of all supplier IDs of which I have received a quote for the respective component.
My approach is the following:
=IFERROR(FILTER('Supplier Responses'!$A:$A; $C147='Supplier Responses'!$C:$C);""), where the "Supplier Responses" tab contains all the quotes. Unfortunately, either the rule cannot be applied or it produces a #SPILL because of too many entries.
I also tried the INDEX-function, which only returns one value though instead of an array.
So how can I turn the array created by the filter function into a dropdown?