If you copy and paste the same clip into your timeline over and over again, they will replay over and over again sequentially as your playhead moves down the timeline. That is the concept. It is not actually a loop, because you are not replaying the same clip, but rather you are replaying the duplicates in sequence so that it is the same effect as a loop.
Therefore, to replay a scene within a clip you need to split out the scene, make one or more duplicates of it, and play them sequentially within the original clip. You can do this with a Modify/Split Clip at the end of the scene you want to replay. Then, on the part of the split off clip that contains the desired scene, outline the scene by putting your cursor at the beginning of the scene and moving your cursor to the end of the clip while holding down the "r" key. You will have created a yellow outline of your scene. Now do an Edit/Copy and Edit/Paste the outlined portion so that it adjoins the scene at the end of the split off clip. When you play and/or share out the whole sequence you will see a replay of the desired scene.
I hope that the above is clear. It is more difficult to explain than to do it. Play around with it for awhile and see if you can make it work.
-- Rich