ID  | Users

1   | John; Bill
2   | Accounting
3   | Engineering

<Query>
   <Where>
    <And>
     <Neq>
      <FieldRef Name="Status"/>
      <Value Type="Text">Completed</Value>
     </Neq>
     <Or>
      <Membership Type="CurrentUserGroups">
        <FieldRef Name="AssignedTo"/>
      </Membership>
      <Eq>
       <FieldRef Name="AssignedTo"/>
       <Value Type="Integer">
         <UserID Type="Integer"/>
       </Value>
      </Eq>
     </Or>
    </And>
   </Where>
</Query>