A lot of Activators have a "Static" version in the item tree under "Static" So look there first to see if one exists , and use that.
But if not look at the path for "Model" on the Activator base object. Then extract it from the BSA and put it in your loose folder ... where you can make a new static in the tree , and search for the model in the loose folder.
Which after saving ... you can delete it from the loose folder , then it will find it in the BSA.
Hope that helps .
Add edit: One point to note ... the folder path in the loose folder needs to be the same as the Archive for it to find it in the Archive after deleting from loose folder ... but if you are leaving it in the loose folder to upload with your mod , doesn't matter to match the path.
In my case, I want to remove the activator from BBQ Grill in TTW. There is no static version in xEdit so I went into the bsa archive and found the model that I need (grillaged.nif). Based on what you said, I need to extract it and pack it into a bsa for my own mod? If that is the case, can I just extract it and put it into meshes/\clutter\grill\ that is not within a bsa? Sorry if I sound dumb, I am pretty newbie to modding.
Yes you need to extract it ... just so you can assign a new static object with that model path (.nif) , because the geck will not browse into the BSA . But it exists in the BSA , so once you assign the model path for a new static object in the tree ... it will then find it in the BSA after deleting the loose folder file , as long as the path is the same.
If you don't know how to extract files from the archive ,,, just look up how to do that ... which I think many of the new mod managers have that feature , instead of needing to use the stand alone extractor utility ... And getting used to using the old tools isn't a bad thing to learn imo . Just what ever your preference is , which I know mod manager tools now have that feature ... but have never used myself ... so can't really advise on that.
Hope that helps.
Add edit: Oh wait ... I missed the point about you using the xEdit tool ... I can't remember if you can create a new base object with that ? If not then have to use Geck ... which is simply done by picking an object of similarity in the same tree location , and reTyping the Base-ID for it . Then select make new object . Now on the new "Static" object you use the model path to find the .nif model in the loose folder / save it ... now delete it from the loose folder. And you will have no worries of uploading that with your mod.