That's Adobe more than onOne or any other software company. It's where the Nik tools would be if you only had one or two of them and not the collection. If you have the Nik Collection you'll find the Nik Selective Tool there (which pops up automatically when you open it, but if you change that preset then that's where you'd invoke it). With the complete onOne package it installed a folder on the bar to the right of the photo frame in Photoshop where the history stack, adjustment properties, and tool presets are. When I click on that it expands left and allows me to choose which onOne tool I want to use, but it's a double click rather than single and I'm still not used to that. Go to Windows->Extensions and there will be an onOne selection if it's there.
In Elements 11 it's in the File->Automation Tools menu as well.