Javascript .filter all items with index less than certain value

Question

I'm trying to filter all the items in the initialItems which has an index lesser than the current item. For example, if the name is CM, i need to get QS, IT and AB to be displayed in a draggable dropdown menu. However, I am stuck on how to use the filter and findIndex javascript function to perform this action.

Code with filter function:

  getItems(itemName) {
    let index = this.state.initialItems.findIndex(x => x.name == itemName);
    for (var i = 0; i < initialItems.length; i++) {
      let items = this.state.initialItems.filter((item) => i < index);

    }
  }

Console.log object of initialItems:

[
    {
        "name": "QS",
        "isTrue": false,
        "id": "ccc"
    },
    {
        "name": "IT",
        "isTrue": null,
        "id": "bbb"
    },
    {
        "name": "AB",
        "isTrue": null,
        "id": "aaa"
    },
    {
        "name": "CM",
        "isTrue": null,
        "id": "ddd"
    }
]

Answer 1

function getItems(itemName) {
  const index = items.findIndex(item => item.name === itemName);
  return items.slice(0, index);
};

getItems("CM");