There are many ways to duplicate clips in the Clips view:
Duplicating clips copies each selected clip and places the duplicates after the last clip on the same track. If you duplicate clips used in a blend or clips separated by a gap, the blend or gap is also duplicated.
If you duplicate an Animation clip that uses a recorded clip as its Source Asset, the recorded clip is also duplicated. The duplicate of the recorded clip only appears in your Project after you save the Scene or Project. For example, the following images demonstrates what happens if you duplicate an Animation clip named "Clip 2B" that uses the recorded clip named "Recorded (3)".
Select the"Clip 2B", hold Command/Control and press D to duplicate
A duplicate Animation clip is placed at the end of the same track. The recorded clip associated with "Clip 2B" is also duplicated.
The new "Recorded (6)" recorded clip appears in the Project window after you save the Scene or Project