IF it's an Ag Leader monitor, you can go into General Options and check the box to show monitor serial numbers for datasets. Then you can filter your tree by operation (Guidance) and date if that works. If you moved the same monitor from sprayer to tractor and have good lines and bad lines from the same one that option is out. 

You can also see the serial numbers in Batch Delete, but again only if you know the serial number and it actually shows up. (it won't for many companies)

Not an easy way to do this since Guidance is its own operation, it's not tied to whatever was going on at the same time. (harvest, tillage, etc)