You cannot wrap any replicating NL function (Rows, Columns, Sheets) inside of an Excel IF() function. Replicating functions must stand alone in a cell.
To make conditional replication work we simply place our IF() function in the Table argument of the replicator and return either the name of the table for which we want to replicate values or an array with one blank value.
This means the replicator will either query a table and replicate its values or return a single blank.
If we wish to list names from the customer table if cell B3=42 our function would look like this: