old_contents: # -*- coding: utf-8 -*-
  # Part of Odoo. See LICENSE file for full copyright and licensing details.
  
  from odoo import fields, models
  
  
  class SlideChannelTagGroup(models.Model):
      _name = 'slide.channel.tag.group'
      _description = 'Channel/Course tags'
      _inherit = 'website.published.mixin'
      _order = 'sequence asc'
  
      name = fields.Char('Name', required=True, translate=True)
      sequence = fields.Integer('Sequence', default=10, index=True, required=True)
      tag_ids = fields.One2many('slide.channel.tag', 'group_id', string='Tags')
  
      def _default_is_published(self):
          return True
  
  
  class SlideChannelTag(models.Model):
      _name = 'slide.channel.tag'
      _description = 'Channel/Course tags'
      _order = 'group_sequence asc, sequence asc'
  
      name = fields.Char('Name', required=True, translate=True)
      sequence = fields.Integer('Sequence', default=10, index=True, required=True)
      group_id = fields.Many2one('slide.channel.tag.group', string='Group', index=True, required=True)
      group_sequence = fields.Integer(
          'Group sequence', related='group_id.sequence',
          index=True, readonly=True, store=True)
      channel_ids = fields.Many2many('slide.channel.tag', 'slide_channel_tag_rel', 'tag_id', 'channel_id', string='Channels')
  
new_contents: # -*- coding: utf-8 -*-
  # Part of Odoo. See LICENSE file for full copyright and licensing details.
  
  from odoo import fields, models
  
  
  class SlideChannelTagGroup(models.Model):
      _name = 'slide.channel.tag.group'
      _description = 'Channel/Course tags'
      _inherit = 'website.published.mixin'
      _order = 'sequence asc'
  
      name = fields.Char('Name', required=True, translate=True)
      sequence = fields.Integer('Sequence', default=10, index=True, required=True)
      tag_ids = fields.One2many('slide.channel.tag', 'group_id', string='Tags')
  
      def _default_is_published(self):
          return True
  
  
  class SlideChannelTag(models.Model):
      _name = 'slide.channel.tag'
      _description = 'Channel/Course tags'
      _order = 'group_sequence asc, sequence asc'
  
      name = fields.Char('Name', required=True, translate=True)
      sequence = fields.Integer('Sequence', default=10, index=True, required=True)
      group_id = fields.Many2one('slide.channel.tag.group', string='Group', index=True, required=True)
      group_sequence = fields.Integer(
          'Group sequence', related='group_id.sequence',
          index=True, readonly=True, store=True)
      channel_ids = fields.Many2many('slide.channel', 'slide_channel_tag_rel', 'tag_id', 'channel_id', string='Channels')
  
subject: fix wrong comodel name in many2many