Active Record LIKE on join query

I may be a little confused, but you should be able to perform your query, then count the number of rows returned in that query using num_rows():

PHP Code:

$temp = $this->input->post('text', TRUE);

if ($temp !== '') {
   $this->db->like('tbl_users.usr_Lastname',  $temp, 'both');
   $this->db->or_like('tbl_groups.grp_Area', $temp, 'both');
   $this->db->or_like('tbl_systems.sys_Location', $temp, 'both');
   // etc., etc.,
}
$this->db->select(
    array(
        'tbl_users.usr_Lastname',
        'tbl_groups.grp_Area',
        'tbl_systems.sys_Location',
        // etc.,
    ), 
    FALSE
)
         ->join('tbl_groupmembers', 'tbl_groupmembers.gm_UserID = tbl_users.usr_UserID', 'inner')
         ->join('tbl_groups', 'tbl_groups.grp_ID = tbl_groupmembers.gm_GroupID', 'inner')
         ->join('tbl_rights', 'tbl_rights.r_GroupID = tbl_groups.grp_ID', 'inner')
         ->join('tbl_systems', 'tbl_systems.sys_ID = tbl_rights.r_SystemID', 'inner');

$query = $this->db->get('tbl_users');

// Record count
$jTableResult['TotalRecordCount'] = $query->num_rows(); 


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