gulp-sass -> Move generated css one folder up and into css folder

Question

I'm switching my old gruntfile for a gulpfile. The project I'm working on has a number of themes, in theme-name.scss it's importing my settings and components from another folder.

This is my file-structure for the themes:

.
├── theme
|   ├── css
|   └── sass
|     └── theme-name.scss
|     └── _theme-settings.scss
├── theme
|   ├── css
|   └── sass
|      └── theme-name.scss
|      └── _theme-settings.scss
|
| Etc...

This is my sass-task:

gulp.task('sass', function () {
    return gulp.src(sassinput, { base: "./" })
    .pipe(sourcemaps.init())
    .pipe(sass({
        includePaths: ['styles'].concat(neat),
        // outputStyle: 'compressed'
    }).on('error', sass.logError))
    .pipe(autoprefixer(autoprefixerOptions))
    .pipe(sourcemaps.write())
    .pipe(gulp.dest("."))
    .pipe(browserSync.stream())
});

I need to compile the *.css in the css folder located in theme folder, and after a lot of trying I managed to get it to compile in the actual sass folder as *.css but I can't seem to go one folder up and in the css folder.

Can anyone give me a pointer as to what I need to do to get it to compile like this:

.
├── theme
|   ├── css
|     └── theme-name.css
|   └── sass
|     └── theme-name.scss
|     └── _theme-settings.scss