applying filters to composite of multiple layers in PS22 and Nik 3.3

My apologies if this is a double posting, new to forum.
Somewhere in Nik settings there is a button allowing to apply Nik filters to a composite of multiple layers or to the current layer only. Somehow it got reset and I cannot find it… Now only the current layer in PS opens in Nik - not the composite. Any suggestions/help?
Thanks in advance!