Need to find something

So I would like a mod+ to find my 2 chests on the new survival map.
How do you do that you may ask. Use the lb command (don’t remember exactly) and find a place were I broke a lot of sand blocks. I broke those blocks about a week or less ago. also I place 2 large chests

This is in a desert/beach biome.

This is how it looked(About).

Legend
W Water
X Nothing
C Chest

Bird’s Eye View
XXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX
WWXXCCXCCXXXXXX
WWXXXXXXXXXXXXX
XXXXXXXXXXXXXXXX

Thank You
God Bless