ngx-admin/src/app/@theme/styles/_overrides.scss

@import './themes';

@mixin nb-overrides() {
  nb-select.size-medium button {
    padding: 0.4375rem 2.2rem 0.4375rem 1.125rem !important;

    nb-icon {
      right: 0.41rem !important;
    }
  }
  
  nb-search button:focus {
    background-color: transparent !important;
    border-color: transparent !important;
  }
}