How to add additional filter to Directus CMS request Angular

I have an issue, where I am not able to add additional search query fields in the request url.

I have a function, that is supposed to get career offers from the CMS, in the code below:

  getCareerOffers() {
    return this.getItems<CareerOffer>('career_offers', ['*', 'image.*', 'content_side_image.*']);
  }

After reading Directus docs, there is a possibility to add an additional query field, to be more specific, in the form of adding [comparator][eq] field, which would look like this:

  getCareerOffers() {
    return this.getItems<CareerOffer>('career_offers', ['*', 'image.*', 'content_side_image.*'], {
      '[company][eq]': 'company',
    });
  }

The issue I am facing, is that I do not really know how to properly proceed. I have been advised, that I should be joining the fields within the function.

Here is how the function looks so far:

private getItems<T>(collection: string, fields?: string[], filter?: Record<string, string>): Observable<T[]> {
    if (!this.cachedObservables[collection]) {


      const prefixedFilters = {}

      const params = {
        ...(fields ? { fields: fields.join() } : prefixedFilters),
        filter: Object.keys(filter).reduce((filtersKey) => {
          const prefixedFilterKey = `filters${filtersKey}`

          prefixedFilters[prefixedFilterKey] = filter[filtersKey]
        }),
      };

      this.cachedObservables[collection] = this.http
        .get<CmsItems<T[]>>(`${this.apiUrl}/items/${collection}`, { params })
        .pipe(
          map(response => response.data),
          publishReplay(1),
          refCount(),
        );
    }

    return this.cachedObservables[collection];
  }

Now, where I am stuck is in the params object, where I can not figure out, how to properly format the filter value.

Object.keys(filter) returns an array with with 0: [company][eq] inside it.

Any ideas on how to achieve it?

I was able to solve it. I was writing my array method wrong. This was the solution that I came up with:

    if (!this.cachedObservables[collection]) {
      const prefixedFilters = {};

      Object.keys(filter).reduce((prefixedFilter, filterKey) => {
        prefixedFilters[`filter${filterKey}`] = filter[filterKey];

        return prefixedFilters;
      }, prefixedFilters);

      const params = {
        ...(fields && { fields: fields.join() }),
        ...prefixedFilters,
      };

      this.cachedObservables[collection] = this.http
        .get<CmsItems<T[]>>(`${this.apiUrl}/items/${collection}`, { params })
        .pipe(
          map(response => response.data),
          publishReplay(1),
          refCount(),
        );
    }