discourse/app/assets/stylesheets/mobile/groups.scss

.groups-page {
  h1 {
    margin-top: 20px;
  }

  .groups-header-filters {
    display: block;
    float: none;
  }

  .groups-header-filters-name,
  .groups-header-filters-type,
  .groups-header-new {
    margin-top: 10px;
  }
  @include breakpoint(mobile-small) {
    .groups-header-filters-name {
      width: 50%;
    }
    .groups-header-filters-type {
      width: 100%;
    }
  }
}