You have to feed XMC with this kind of data via NAC information. There's a tool called compass search where you can search for this kind of data on demand. It's a live search (via snmp) and the data does not go into the Database. If you run SPBM fabric, then compass search is only able to search in VRF0 (GRT). Not very usefull when you have several VRFs. If you have the fabric manager, you can obtain more information like i-SID, L3VSN etc., but this data does not go to the Database.
Following because I would love to have this also and hope someone has a better answer.
My current thought is write a script that will get the mac-address-table from all switches and the ARP tables from my distribution and core switches and then dump it into a CSV and run it nightly or as needed. Haven't had the time to test this yet to see if it's feasible though.