[SOLVED] Invisible space on hdd

[piagraffy2]

Hello, my HDD is almost full but there is nothing on this Mac at all.

I'm running High Sierra 10.13.2, when I go into the disk utility and select HDD it says 'shared by 4 volumes' even though there is only 1 extra volume (windows bootcamp) this happened in the past and I had to format the hdd and reinstall the OS but that didn't make a difference, is there any way to view the volumes and remove them/unpartrition?

 

[spinningstill]

What does get info say about the HDD? Often it is TM doing back ups. Does it tell you, you can't add anything or getting the "almost full" error?