Control Life cycle of Niagara with a Blueprint

Hello everyone,
The screenshot I am attaching comes from a tutorial.
This allows you to slow down or speed up the reading of a niagara. 0 = freezes, 1 = normal speed, > accelerates.
I am always looking with a BP to modify or reproduce the lyfe cycle and make the system reduce and disappear.
Another question how to read a Niagara System backwards.
Yours sincerely
Denis