Ok I’m losing my mind! So i have to have billboard as root to get this effect? I swear i tried this and it didn’t work! Thanks for sticking with me here.
Here is a resume of how i did :
In a 4.5 project, i create a new blueprint. I save and open.
In tab component :
I add a billboard (not material billboard), a spline (not spline mesh) and a Static mesh (with SM_Chair selected in starter content props).
I up z of the spline to 10 to not have it in ground (but it works too underground, i tried, but hum it is underground ^^).
I compile and save.
In Graph :
i add elements in the order from left to right, and up to down (some need to uncheck context sensitive to be found). Timeline length is 3s / track is a float with 2 keys 0s.0 / 3s.1 set with loop and auto play checked to visualize.
Edit : In this setting mesh will face the direction of the spline, you can use a track float in timeline to create any other rotation you want)
Compile and save.
In level Blueprint : I add the blueprint, select the spline point and add / move new ones.
Compile and save. Play.
Beware that your spline points are reseted or not in your level when you do modifications in your graph. You’ll have to do them again (this is maybe the trouble you had when you tried with billboard added and that it seemed not working).
Ok I think i found the problem. So I guess you can’t move a box component or the entire BP, you can only move mesh or particle. I’m trying to move to whole BP along the spline to the end, then be able to move it again after it stops at end location, move along the spline to new location and so on. Is this possible? Or do i need to find a different option? If there is a way to use “move component to” node and get same result that would work too. But I can only get it to go to one point on the spline with that node.
Ok ! To move your actor, you’d better use the other timeline then like this :
Edit : This is a normal timeline with no billboard / splines. And you can do the same with splines but you need to set actor location on finished timeline output.
Hey thanks for all the help! I have the timeline working the way i wanted by putting a auto curve on first key for Y and user on key 2. Now it goes to the same spot every time 'I think" lol or it looks dang close. Your awesome for all that you have shown me! Is it cool to DM you for any other Q & A?
Sure. I can’t promise to know but i can promise to try 
Hey Two heads are better then one! I’m an army of one and this is my hobby, so any pointers I can get to speed things up is much appreciates.
To not have variations with a float track and be able to use exact values : Set “start” and “end” vector variables before “play” timeline and use them in “lerp vector” instead of directly using infos like " get actor location"