Which version of Lightroom are you using?
Unless you are using Lightroom CC (the creative cloud-subscription version) you won't have that filter. It is not available in Lightroom 6.
I am using the creative cloud version
Check the help/about dialog for the version you are running and what licensing mode LR is running in.
When LR prompts me for the licensing login (far more frequently than 30 days), it drops into LR6 mode instead of LRCC mode and does not come back into LRCC mode until I restart LR.