var result = value;
if (value.length === 3) {
    var base = thisComp.layer("BASE");
    if (base.index !== index) {
        var position = base.transform.position.value;
        if (position.length === 3) {
            result = [position[0], position[1], position[2] + 3000];
        }
    }
}
result;
