There are 6 senses in Buddhism:
Sight, hearing, smell, taste, touch and will.
There are three ways of receiving this feeling: comfortable, uncomfortable, and in between.
In addition, they are divided into two categories: clean and dirty.
This results in: 6 x 3 x 2 = 36
This „process“ is divided into the space-time axis of the previous life, the present world and that of the hereafter:
36 x 3 = 108
There are other philosophical views on this.