App To Show What Files Are Taking Up The Most Space

This may well have been answered elsewhere and if so then feel free to direct me to that post.
I’m looking for an app or utility that will graphically show me what kinds of files I have on my WD NAS drive and how much space they are each taking up. I have that ability for my local C: & D: drives but not my Z: (WD NAS) drive. Perhaps WD has a utility such as this available and I’ve just not stumbled across it yet. At any rate, I’ve run “duplicate finders” and what-not but in spite of that my 3TB drive remains nearly at full capacity and I still can’t accurately identify exactly what is filling it up so I can figure out what to get rid of.

This will tell you what is taking up space. is another one.

“DiskSavvy is a disk space usage analyzer capable of analyzing disks, network shares, NAS devices and enterprise storage systems. Users are provided with multiple disk usage analysis and file classification capabilities allowing one to gain an in-depth visibility into how the disk space is used, save reports and perform file management operations.”

I use Directory Report
It looks just like the MS-Explorer but always shows the folder size
You can get a summary file types and their size by selecting menu: Largest / Display Largest Type

TreeSizeFree for Windows.
du -sh * | sort -h for SSH.