private function get_filtered_items( $assoc_args, $filter_field = '' ) {

		$addons = llms_get_add_ons();

		$list = array_filter(
			$addons['items'],
			function( $item ) {
				return // Skip anything without a slug.
				! empty( $item['slug'] ) &&
				// Skip the LifterLMS core.
				'lifterlms' !== $item['slug'] &&
				// Skip third party add-ons.
				! in_array( 'third-party', array_keys( $item['categories'] ), true );
			}
		);

		// Format remaining items.
		$list = array_map( array( $this, 'format_item' ), $list );

		// Filter by field value.
		if ( $filter_field ) {
			$field_val = $assoc_args[ $filter_field ];
			$list      = array_filter(
				$list,
				function( $item ) use ( $filter_field, $field_val ) {
					return $item[ $filter_field ] === $field_val;
				}
			);
		}

		// Alpha sort the list by slug.
		usort(
			$list,
			function( $a, $b ) {
				return strcmp( $a['name'], $b['name'] );
			}
		);

		return $list;

	}