Considering that you want to use a different archive than the default TLA one, you should add that as a remote location. For that, in the IMDI Browser go to the root node of your tree, click on ‘create bookmark’ and copy the URL (should look somewhat like http://dobes.caicyt.gov.ar/somethingsomething/blabla.imdi). Then in Arbil right click on the Remote corpus, choose ‘add remote location’ and paste the URL into the box that appears. After you click okay, Arbil should show the tree of your archive in the Remote Corpus section as well and you can import things from there into your local corpus normally.