MIM itself does not have a command to show the latest maintenance.
There is, however, the CA Common Services command CAMODID.
You can use this at the TSO command prompt.
From TSO, issue CAMODID HELP to see what's all available.
There are various options; DSN, DDN, or SYSTEM.
Please review the manual for additional information regarding all the ways in which you can invoke the command - TSO, batchjob, REXX, etc.
If you have the CBTDLOAD in your LINKLIST, this command
CAMODID SYSTEM LMOD(MIM)
will display all PTFs for modules that start with MIMxxxxx (which includes the entire library)
If you are using a STEPLIB in your MIMPROC, you can use this command
CAMODID DDN(STEPLIB) JOB(mimstcname)
Other options are available to suit your specific needs.