where can i see 2 different computer back ups on time machine?

Locate the Time Capsule icon on the left panel of any Finder window under the Shared heading

Use the Finder to mount the Time Capsule disk on your Mac's desktop. The drive is named "Data", unless you have changed it. You may be asked for the Time Capsule device password when you do this.

Once "Data" is mounted on your desktop, go ahead and open up the drive.

You will see a special sparsebundle file for each Mac that has backed up to the Time Capsule with the name of Mac included in the name of the file

If you do not see a file with the name of the other Mac, then the other Mac was not backed up.

Double click the sparsebundle file for the Mac whose backups you want to see and that will mount another disk icon on the desktop named Time Machine Backups

Open Time Machine Backups and a normal folder named Backups.backupdb will appear.

Open that folder. You will have to drill down a number of layers to find the files that you are looking for.

It is OK to copy a backup file(s), but you will need to be very careful to not change or modify any of the files in any way.