<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def groups_dynamic(self):
 """ returns dynamic relationship for groups - allowing for filtering of data """

        return sa.orm.relationship(
            "Group",
            secondary="users_groups",
            lazy="dynamic",
            passive_deletes=True,
            passive_updates=True,
        )