Facebook doesn't make it very easy to embed videos, but we've figured out how to make this work for you:
1. On this page you'll find a mechanism for producing the proper code to embed your videos on your site (maybe you already did this part). You put in the URL of your video, and when you click the button to "Get Code", you get a popup, with two boxes of code.
3. You also need to make sure that the forum you are in allows HTML, and that you have given yourself the permission to post HTML (we don't usually recommend that you give ALL members that permission, but you might want to give that permission to people you trust, if you want them to post Facebook videos). To make sure the forum allows it, go to Forums>>Specific Forums, then click "Forum Details" next to the forum in question. On the Posting Settings tab, uncheck the box that says "Disable HTML", and then Update Settings at the bottom of the page. Now make sure that you have permission to post HTML via the Permission Snapshot (Eve>>Members>>Permission Snapshot) This is a Personal Permission, and you can choose to allow a power group, or specific users (such as yourself).
4. Now you're ready to embed the Facebook Video. From the developer page I showed you earlier, copy the code from 2. "Place the code from your plugin..." box. You can paste that into a posting form on the forum, and you don't need the filmstrip tags (this is not a flash video), so you can just paste it in as it is.
Note that, once whatever themes you are using have the code from 1. in the "Insert AFTER Opening Body Tag" field, you won't have to repeat that step any more. Same with allowing HTML in any forum that you need to post Facebook videos in. You'll just need to get the code from the video embed code generator.
Hope this helps!