imposed motion

If I understand your question correctly, you want to apply a time history to specific joints, and not as a general global motion (as you would for an earthquake time history)?

Then yes, you can: (this example considers imposed displacements)

1. define a load case (ex. DISPLACEMENT)

2. assign a unit displacement (assuming that the time history is scaled to the values you want) to the joint. Make sure it is applied under the DISPLACEMENT load case.

3. define a time history case (ex. a sine function, SINE).

4. define an analysis case (ex. TH). Select a (linear or nonlinear) time history analysis case type. Choose Load as your load type, DISPLACEMENT as the load name, and SINE as your function.

Now, when you run your analysis case TH, your joint will be subjected to the motions from your time history.

In principle, you should be able to apply different time histories to different joints at the same time - however I have never encountered this task before.

Good luck!

To impose a displacement to some selected nodes?
Select joint go to assign > joint load >displacement.