How to Mount a Sparsebundle Disk Image from Time Machine Backup?
If you are ok with creating a temporary shadow file, you can mount it this way:

hdiutil attach -shadow /path/to/store/the/temporary/file.shadow /Volumes/Backup/Backups.backupdb/MachineName/Latest/Path/To/Image.sparsebundle


For succinctness, that is: hdiutil attach -shadow &lt;shadowfile&gt; &lt;imagefile&gt;

Edit: in a previous version of my answer I included the -readonly flag in the command, but I've found that it will sometimes fail with "no mountable file systems" when -readonly is passed. Omitting the flag in these cases allowed the image to be mounted successfully.

As such, I've updated the answer to exclude the -readonly flag. Just note that any changes you make in rw mode will only be written to the shadow file.