wpmem_query_where

/**
 * This adds a custom query that can be used in the Users > All Users filtered views.
 * 
 * Set the variables according to comments noted in the snippet.  You will need to 
 * set values for the $view_name (a unique slug), $meta_key, and $meta_value as
 * noted below. 
 */
add_filter( 'wpmem_query_where', function( $query_where, $show ) {
    
    // Set these accordingly:
    
    // The view name: 
    $view_name  = 'my_unique_view_name';
    
    // The meta key of the field you are filtering by:
    $meta_key   = 'my_field_meta_key';
    
    // The value of the field you want to filter by:
    $meta_value = 'the field value';
    
    // Don't change this:
    $query_where = wpmem_add_query_where( $query_where, $view_name, $meta_key, $meta_value );
    return $query_where;
}, 10, 2 );


/**
 * This adds the link for the custom query you created above.
 * 
 * Similar to the snippet above, you'll need to set the variable values
 * to be used.  Note that some of them need to be the same as what you
 * set in the above snippet (the field name and value and the filter name).
 */
add_filter( 'wpmem_views_users', function( $views, $show ) {
    
    // Displayed value of your filter link in Users > All Users
    $name = "My Filter View";
    
    // Custom view name (should match $view_name used above)
    $view_name = "my_unique_view_name";
    
    // The meta key of the field you are filtering by (should
    // match what you're using above, this is for the count)
    $meta_key   = 'my_field_meta_key';
    
    // The value of the field you want to filter by (should
    // match what you're using above, this is for the count)
    $meta_value = 'the field value';
    
    // Don't change this:
    $views = wpmem_add_user_view_link( $views, $name, $view_name, $meta_key, $meta_value );
    return $views;
}, 10, 2 );