This code snippet prevents members from being able to see themselves in the member directory.

um_member_directory_notme.php

<?php

/**
 * Prevent members from being able to see themselves in the member directory.
 * Add this code to the file functions.php in the active theme directory.
 */

function um_pre_users_query_notme( $directory ) {
	if ( is_user_logged_in() ) {
		$directory->where_clauses[] = 'u.ID != ' . get_current_user_id();
	}
}
add_action( 'um_pre_users_query', 'um_pre_users_query_notme', 20 );

function um_prepare_user_query_args_notme( $query_args ) {
	if ( is_user_logged_in() ) {
		$query_args['exclude'] = get_current_user_id();
	}
	return $query_args;
}
add_filter( 'um_prepare_user_query_args', 'um_prepare_user_query_args_notme', 20 );

This gist is a part of the article Prevent members from being able to see themselves in the member directory.

Documentation: https://docs.ultimatemember.com/
Support forum: https://wordpress.org/support/plugin/ultimate-member/
Support (for customers): https://ultimatemember.com/support/ticket/