variations.js

const data={
    variants: [
      {
        id: 'ae020c58-5d83-4665-9e5f-af3f21f80371',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '7',
          color: 'pink'
        },
        slug: null
      },
      {
        id: '0106daa9-c355-4699-8502-319fec8a7ca9',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '7',
          color: 'gree'
        },
        slug: null
      },
      {
        id: '0425703f-69f9-493d-bf45-f0ebb13620bc',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '7',
          color: 'red'
        },
        slug: null
      },
      {
        id: '19b73ae6-a7ba-4c2d-bda3-87037b0b1ab1',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '6',
          color: 'pink'
        },
        slug: null
      },
      {
        id: '1f193290-600d-4b30-a634-1234735b4ab3',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '6',
          color: 'gree'
        },
        slug: null
      },
      {
        id: 'd060a0a7-1062-4d10-844a-1d98b894b4dc',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '6',
          color: 'red'
        },
        slug: null
      },
      {
        id: 'e7d2390e-2cbf-4778-8242-f149d3975d63',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '5',
          color: 'pink'
        },
        slug: null
      },
      {
        id: '1341e073-e723-4173-8566-fc63bc37f7a8',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '5',
          color: 'gree'
        },
        slug: null
      },
      {
        id: '3df810e8-bb80-4dcc-aa98-c4185976bb5d',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '5',
          color: 'red'
        },
        slug: null
      },
      {
        id: '494149b8-44bf-4781-b93d-03a94e0da0d4',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '4',
          color: 'pink'
        },
        slug: null
      },
      {
        id: '5d5423c2-e18b-41b2-83df-d8ea2571b3cc',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '4',
          color: 'gree'
        },
        slug: null
      },
      {
        id: '1d0873d0-7e58-4df8-b586-19a4e0da53e3',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '4',
          color: 'red'
        },
        slug: null
      },
      {
        id: '4f1107aa-a944-4423-a04a-b7691a0c6a22',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '3',
          color: 'pink'
        },
        slug: null
      },
      {
        id: '8bfc0e88-4fd5-4578-b319-da9909f848fb',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '3',
          color: 'gree'
        },
        slug: null
      },
      {
        id: '383c970e-6158-4f78-a5e4-1da700c113c5',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '3',
          color: 'red'
        },
        slug: null
      },
      {
        id: '54c6efe4-1d52-4111-a933-e8fe745ac228',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '2',
          color: 'pink'
        },
        slug: null
      },
      {
        id: '24946e17-9759-4c9d-b627-eb36a9da913a',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '2',
          color: 'gree'
        },
        slug: null
      },
      {
        id: 'd1c75b28-52e1-44a8-92e8-42e79a7618ca',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '2',
          color: 'red'
        },
        slug: null
      },
      {
        id: 'dc04dabd-3e24-4a4c-8ab4-45bcc69f26ac',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '1',
          color: 'pink'
        },
        slug: null
      },
      {
        id: '95369e7d-6f2d-463c-a411-62a32f91104c',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '1',
          color: 'gree'
        },
        slug: null
      },
      {
        id: '9703d229-5a76-446a-872f-41f08d21d38b',
        product: '800402fc-b0cb-4bbe-8380-3bcee92f3bf9',
        category_type: 'productvariants',
        products_metadata: {},
        thumbnail: null,
        thumbnail_frontend: null,
        quantity: 1,
        attributes: {
          size: '1',
          color: 'red'
        },
        slug: null
      }
    ],
};

solution kaka

const map = {};

data.variants.map((variant) => {
  const { color, size } = variant.attributes;
  if (map[color]) {
    map[color].push(size);
  } else {
    map[color] = [size];
  }
});

console.log(JSON.stringify(map, null, '\t'));

or fancier

const map = {};

[...new Set(data.variants.map(({ attributes: { color } }) => color))].map(color => map[color] = []);

data.variants.map(({ attributes: { color, size } }) => map[color].push(size));

console.log(JSON.stringify(map, null, '\t'));