.bemrc-example.js

module.exports = {
    root: true,

    levels: [
        // Ordered array of levels if you need a specific order between levels in library or project
        {
            layer: 'common', // Должен быть уникальным
            path: 'very-uncommon.blocks', // если сильно хочется (?)
            fs: { scheme: 'flat', naming: 'secondary' },
            naming: 'primary'
        },
        // Сначала более общие
        { layer: 'deskpad' },
        { layer: 'touch' },
        // Потом более частные
        { layer: 'desktop' },
        { layer: 'touch-phone' },
        'touch-phone', // Можно вообще строкой
        'touch-pad',
    ],

    libraries: {
        'bem-components': { /* looks for `node_modules/${id}` by default */ },
    },

    sets: {
        // Will use `touch-phone` set from bem-components and few local levels
        'touch-phone': '@bem-components/touch-phone common touch touch-phone',
        'touch-pad': '@bem-components common deskpad touch touch-pad',
        // Will use `desktop` set from `bem-components`, and also few local levels
        'desktop': '@bem-components common deskpad desktop',        
        // Will use mix of levels from `desktop` and `touch-pad` level sets from `core`, `bem-components` and locals
        'deskpad': 'desktop@core touch-pad@core desktop@bem-components touch-pad@bem-components desktop@ touch-pad@'
    },
        
    // !!! in libs/bem-components/.bemrc.js
    libraries: {
        core: { path: 'node_modules/bem-core' },
    },
    sets: {
        'desktop': '@core common desktop',
        'touch-pad': '@core common touch touch-pad',
        'touch-phone': '@core common touch touch-phone'
    },
    
    modules: { /*…*/ }
};

dumki.js

    // blocks/button/button.css
    // button.css // common
    // button@desktop.css
    // common.blocks/button/button.css
    // blocks-common/button/button.css
    // touch/button.css
    // button@touch.css
 
    // `blocks/{entity}{layer && later !== 'common' ? `@{layer}` : ''}.{tech}`
    // `{layer ? `{layer}.` : ''}blocks/{entity}.{tech}`

module.exports = {
    sets: {
        'custom': '@desktop @touch-pad', // common deskpad desktop touch touch-pad
                                         // commmon deskpad touch desktop touch-pad
    }
};

    //core
    levels:
      common
      touch-pad
      desktop
    //comp
    levels:
      common
      desktop
      touch-pad
    

index.js

const BemConfig = require('@bem/sdk.config');

const bemconf = new BemConfig();
(async () => {
  console.log(await bemconf.levels('desktop')); // set (platform)
  // [ { path: 'common.blocks' }, { 'deskpad.blocks' }, { 'desktop.blocks' } ]
})();

xxx.js

const walk = require('@bem/sdk.walk');
const Config = require('@bem/sdk.config');
// const { walk, Config } = require('@bem/sdk');

const config = new Config({
    /*?*/
    defaults: {
        naming: {}, // ?
        schema: {}, // ?
        // ?
    }
});

await walk.asArray({
//    levels: ['i-bem', './islands'],
    set: 'desktop', // or array
    cwd: process.cwd()
    config
});


walk([], { path });


// i-bem/.bemrc: {schema: 'legacy', levels: [{layer: 'common'}, {layer: 'desktop'}], sets: {desktop: ['common']}}
// i-bem/common.blocks/*
// islands/.bemrc: {schema: 'legacy', sets: {desktop: ['common', 'desktop', {layer: 'qwe', lib: 'asd'}]}}
// islands/common.blocks/*
// islands/desktop.blocks/*