How can I set some Next-Previous buttons?

The situation is the follwing: I want to deliver a game setup where animations on the sequencer pass like sliders. To execute this I added two buttons: a previous button and a next button. The thing is that I don’t know how to make this two buttons work, or, in other words, make that whenever I press that single button it could pass slide, after slide, after slide…

I don’t know either if the solution are Integers or no.

Can someone help please?

Thanks.