Noticed very large space utilisation in linux LVs, how to find which file or what is responsible here?

Question

I have two disks in my server with a LVs created and issue is on the one mounted on /.

I am aware of using find and sort to output the largest for some given number of lines. like:

find / -type f -exec du -Sh {} + | sort -rh | head -n 10*

Below is the output for the lsblk:

NAME              MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                 8:0    1 931.5G  0 disk 
├─sda1              8:1    1     1G  0 part /boot
├─sda2              8:2    1     4G  0 part [SWAP]
└─sda3              8:3    1 926.5G  0 part 
  ├─vg00-root_vol 253:0    0 925.5G  0 lvm  /
  └─vg00-lv_tmp   253:1    0     1G  0 lvm  /tmp
sdb                 8:16   1   1.8T  0 disk /builds

But this does not add up to the total 811G usage as seen above. What else could be occupying this space and how to locate this?

The df -h command indicates 88% utilization as seen below:

Filesystem                 Size  Used Avail Use% Mounted on
devtmpfs                    63G     0   63G   0% /dev
tmpfs                       63G     0   63G   0% /dev/shm
tmpfs                       63G  4.1G   59G   7% /run
tmpfs                       63G     0   63G   0% /sys/fs/cgroup
/dev/mapper/vg00-root_vol  926G  809G  117G  88% /
/dev/sdb                   1.8T  1.3T  491G  72% /builds
/dev/mapper/vg00-lv_tmp   1014M   40M  975M   4% /tmp
/dev/sda1                 1014M  231M  784M  23% /boot
tmpfs                       13G   24K   13G   1% /run/user/0
tmpfs                       13G   16K   13G   1% /run/user/42