Hi all

i added  a many2many field on timesheet view which display all the project available on timesheet line.

this is the code :

project_ids = fields.Many2many('project.project', relation='timesheet_project_rel', string='Project',

                                   compute='_get_default_project')

    @api.depends('line_ids.project_id')

    def _get_default_project(self):

        project_ids = []

        lst = []

        for sheet in self:

            for rec in sheet.line_ids:

                project_ids.append(rec.project_id.id)

            sheet.update({'project_ids': [(6, 0, project_ids)]})

and on xml :

<filter string="List Of project" name="groupby_project_ids" domain="[]"

                        context="{'group_by':'project_ids'}"/>

But i'm  getting an error on filter of the list project because we can not group by many2many fields 

Can any have another solution for help me ?

thanks in advance.