The default group by registration week has been removed in the attendee view because: - it makes the view impossible to use on mobile (too many columns) - it makes the navigation on desktop a bit tricky This reverts a change introduced in odoo/odoo@4bed87d. Task 2761011 closes odoo/odoo#85113 X-original-commit: 7ebc86fd9202a0023513a2d4535f93a2d3914c1d Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>