A waiting thread will show in the Monitoring plugin like this:
"http-bio-9029-exec-3493" daemon prio=5 TIMED_WAITING
But on host-url/threadDump screen it'll give more information on the object that is being waited for:
"http-bio-9029-exec-3493" Id=194353 Group=main TIMED_WAITING on com.sun.jndi.ldap.LdapRequest@10f324c

This goes the same for Blocked state.
Without this information the thread-dump feature becomes kind of useless in these situations.