Not quite sure who is responsible for this, but when WIFF2 got added, rather than creating a new data source type for it we just combined it with the existing WIFF type. But typically SCIEX now puts both a WIFF and a WIFF2 file in the same folder for each acquisition. So, it may be fairly common that a user would want to hide either all WIFF2 files or all WIFF files to open a set of one kind or the other. Opening both would be far less common since it would duplicate the data.

I found this pretty frustrating working with a user. Though, I was eventually able to get the separation I wanted by switching to the details view and sorting by size, because even in the details view the file type is listed as WIFF/WIFF2. So, you can't sort by file type! Luckily the WIFF2 files were universally larger than the WIFF files.

Let's fix this to separate the two file types. I can't really see the case where you would want to be viewing both at the same time. Or if you did, you could just use All Types.