folder_exclude_patterns relative to project root

[kokokurak]

I want to exclude /vendor folder, relative to the project root. In other words, not my-project/kitten/vendor, not my-project/some/very/deep/folder/vendor, but just my-project/vendor.

By default, if I put this to my .sublime-project file, all vendor folders are excluded:

"folders":
[
    {
        "folder_exclude_patterns":
        [
            "vendor"
        ],
        "name": "My Project",
        "path": "~/www/my-project"
    }
]

I would expect this to work as I need, but unfortunetely not:

"folder_exclude_patterns":
[
    "/vendor"
],

Is there any other way to put pattern relative to the folder?