An object at rest with respect to one object can be in motion with respect to another object. Do you agree? Give an example to prove your point.

Yes, I agree. Whether an object is at rest or in motion depends on the frame of reference or the point of observation. For example, if a man A and man B are sitting inside the bus and a third man C is standing outside. Now, if the bus starts moving then man A will see man B at rest no matter how fast the bus is moving. But, man C will see man B moving along with the bus, for him man B is moving with the speed of the bus. So, we can say that man B is rest with respect to man A but he is moving with respect to man C. The difference in observations comes due to different points of observation or different frame of reference.