Factor  Fields

Passes a value from 0 to 1 for each index. The main task of the node is to replace other fields when it is required to animate according to an ordered index.

Based on this lesson: https://www.youtube.com/watch?v=V6bJP88zuYw&t=103s

Settings

Factor– The slider is from 0 to 1. It is calculated as the number divided by 1. Thus, if you have 2 objects, then if the factor value is 0.5, then the index 1 will get the value 1.
Index Count – The number of indexes to influence.

The Colorramp or Float Curve is used to add softness or contrast to the values. You can also set different behaviors such as bounces

How to use
Motion Node Factor Fields 1
Motion Node Factor Fields 2
Factor value is 0.5, index 1 will get the value 1.
In action